#isa — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #isa, aggregated by home.social.
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pack it up everyone, no point in doing #ISA design anymore; Tachyum has released the Universal Processor ISA!
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pack it up everyone, no point in doing #ISA design anymore; Tachyum has released the Universal Processor ISA!
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💻 Happy Nat'l IBM PC Day! — August 12, 2026
IBM PC Day, observed every August 12, commemorates the launch of the original IBM Personal Computer in 1981. IBM5150.net
#IBMPCDay #NatlToday #IBM #PC #1981 #8080 #8088 #8Bit #16Bit #MicroComputer #16kBRAM #RAM #ROM #Floppy #I/O #ISA #eISA #Serial #DotMatrix #BIOS #DOS #Prompt #CommandLine #OS #Intel #DialUp #BBS #ShareWare #RetroComputing #ComputerHistory
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Curious how a tax wrapper helps your investments? It can shelter gains, but what protections exist if your broker goes bust? Before you sign up, ask these questions. BrokerCue’s guide to broker insolvency explains what happens to your money and assets when a firm fails. Don’t leave your nest egg unprotected.
#investing #taxwrapper #isa #financialliteracy #brokerinsolvency #investorprotection
https://brokercue.com/blog/broker-insolvency-what-happens-to-investments/
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Stranger things in the heat!
In my city of Reno, the average temperature has increased about 7 degrees on average since the 1970s, making it one of the fastest warming cities in the nation. For the trees, it means there are new parameters for pests to live here where they wouldn’t have survived otherwise. This year I’ve seen two new issues I’ve never seen before, and they were both spotted about a week apart in the peak of the summer. This marking was found on a Quaking Aspen (Populus tremuloides) and I really […]https://garesgarden.wordpress.com/2026/08/06/stranger-things-in-the-heat/
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Stranger things in the heat!
In my city of Reno, the average temperature has increased about 7 degrees on average since the 1970s, making it one of the fastest warming cities in the nation. For the trees, it means there are new parameters for pests to live here where they wouldn’t have survived otherwise. This year I’ve seen two new issues I’ve never seen before, and they were both spotted about a week apart in the peak of the summer. This marking was found on a Quaking Aspen (Populus tremuloides) and I really […]https://garesgarden.wordpress.com/2026/08/06/stranger-things-in-the-heat/
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Viele 🚗 🚚 🚗 treffen sich gerade auf der A3: Köln -> Frankfurt, zwischen 2.4 km hinter AK Köln-Ost und 3.1 km vor AS Niedernhausen und blockieren die #Autobahn.
Es könnte sein, dass sie heute die #EU-weit verpflichtende Installation eines intelligenten, übersteuerbaren Geschwindigkeitsassistenten in alle #Neufahrzeuge fordern. Das könnte langfristig die Zahl der #Verkehrstoten um 20% reduzieren. Viel weniger Autos hätten #Totalschaden. 🚗⚠️ #Verkehrssicherheit #ISA (Quelle: ETSC)
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Viele 🚗 🚚 🚗 treffen sich gerade auf der A3: Köln -> Frankfurt, zwischen 2.4 km hinter AK Köln-Ost und 3.1 km vor AS Niedernhausen und blockieren die #Autobahn.
Es könnte sein, dass sie heute die #EU-weit verpflichtende Installation eines intelligenten, übersteuerbaren Geschwindigkeitsassistenten in alle #Neufahrzeuge fordern. Das könnte langfristig die Zahl der #Verkehrstoten um 20% reduzieren. Viel weniger Autos hätten #Totalschaden. 🚗⚠️ #Verkehrssicherheit #ISA (Quelle: ETSC)
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Moneybox got 1.5 million people saving, but its Stocks and Shares ISA charges about £57 a year on £10k for what Trading 212 does for free. Same index funds, four times the cost.
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https://www.wacoca.com/life/436225/ Korea Investment & Securities、MTSの国内株・ETF画面を刷新 #ETF #investment #isa #KoreaInvestmentSecurities #MTS #toshi #国内株 #投資
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BrokerCue compares regulated brokers. A tax wrapper like an ISA keeps your money growing tax free. Imagine you hold £10,000 in a Stocks and Shares ISA when your broker becomes insolvent. Your shares remain yours, ring fenced and separate from the broker’s own assets. You can transfer them to another provider without losing your tax benefits.
#investing #taxwrapper #isa #brokerinsolvency #personalfinance #savings
https://brokercue.com/blog/broker-insolvency-what-happens-to-investments/
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BrokerCue compares regulated brokers. Tax wrappers like an ISA or SIPP keep your investments in a segregated account away from the broker's own assets. For example, if you hold £50,000 in a stocks and shares ISA and your broker goes under, those client assets remain protected and are not used to pay the broker's debts.
#investing #tax #personalfinance #isa #financialeducation #moneytips
https://brokercue.com/blog/broker-insolvency-what-happens-to-investments/
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Yöllä #isä saapui innoissaan lehdestä leikattu #kuponki kädessään äitini luokse kertomaan päättäneensä ostaa #nurmipyörä'n. Se oli kolmipyöräinen #polkupyörä, jossa oli iso eturitsi, ja se maksoi 150 €. Sitten hän kuitenkin huomasi alalaidasta pienellä kirjoitetun tekstin: ”tällä päivämäärällä tuote on loppuunmyyty”, ja tänäinen päiväys. Etsin verkosta toisen liikkeen vastaavia, ja halvin maksoi 175 €. Isäni ja naapurinmies pudistelivat ankeina päätään: oli liian kova hinta. #unet
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Yöllä #isä saapui innoissaan lehdestä leikattu #kuponki kädessään äitini luokse kertomaan päättäneensä ostaa #nurmipyörä'n. Se oli kolmipyöräinen #polkupyörä, jossa oli iso eturitsi, ja se maksoi 150 €. Sitten hän kuitenkin huomasi alalaidasta pienellä kirjoitetun tekstin: ”tällä päivämäärällä tuote on loppuunmyyty”, ja tänäinen päiväys. Etsin verkosta toisen liikkeen vastaavia, ja halvin maksoi 175 €. Isäni ja naapurinmies pudistelivat ankeina päätään: oli liian kova hinta. #unet
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📬 EU plant Tempo-Bremse mit Satellitentechnik
#Cyberangriffe #Datenschutz #AllianceofBritishDrivers #Bevormundungsstaat #BrianGregory #Geschwindigkeitsassistent #Isa #Neufahrzeuge #TempoBremse https://sc.tarnkappe.info/2a07d9 -
📬 EU plant Tempo-Bremse mit Satellitentechnik
#Cyberangriffe #Datenschutz #AllianceofBritishDrivers #Bevormundungsstaat #BrianGregory #Geschwindigkeitsassistent #Isa #Neufahrzeuge #TempoBremse https://sc.tarnkappe.info/2a07d9 -
Moneybox got 1.5 million people saving, but its Stocks and Shares ISA charges about £57 a year on £10k for what Trading 212 does for free. Same index funds, four times the cost.
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Protagonismo jovem e justiça climática: como territórios vulneráveis lideram a adaptação ao extremo
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Protagonismo jovem e justiça climática: como territórios vulneráveis lideram a adaptação ao extremo
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Mr. Mahathir is a dictator. He has used his power to abuse others. I will never wish him a happy 101st birthday. Vomit emojis.
#Mahathir #Malaysia #dictator #dictatorship #politics #birthday #HappyBirthday #ISA #corrupt #corruption #government #history
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Mr. Mahathir is a dictator. He has used his power to abuse others. I will never wish him a happy 101st birthday. Vomit emojis.
#Mahathir #Malaysia #dictator #dictatorship #politics #birthday #HappyBirthday #ISA #corrupt #corruption #government #history
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PDS – the Programmers Development System – Part 5
In this part I’m finally getting to properly test the boards, having finally managed to acquire all the parts I need: namely a working ZX Spectrum, an ISA based PC and the means to get software onto them both.
- Part 1 – Introduction, background and some initial reverse engineering.
- Part 2 – A closer look at the PC ISA Interface card.
- Part 3 – Remaking the target interfaces.
- Part 4 – Building the boards.
- Part 5 – Getting everything running (first, unsuccessful attempt).
- Part 6 – Some serious diagnostics and a breakthrough (at last)!
- Part 7 – Diagnostic module PCB.
- Find it on GitHub here: https://github.com/diyelectromusic/PDS_Remake
In terms of documentation for using the PDS, I have found the following:
- PDS IBM Editor Manual: “The_PDS_Editor_Manual.pdf”
- PDS Z80 Manual: “The_PDS_Z80_Manual.pdf”, “P.D.S.Manual.pdf”, “Manual_PDS”
The first describes how to install and use the PC software. The second describes the syntax and functionality of the assembler, and the technical details of the PC to ZX Spectrum target parallel interface.
PC Software
The PC side of the system can be found online in the file “P.D.S._PC-Software” which extracts out to the following:
demos\
arce.com
dopds.bar
pdsz80.exe
read.8
read.meThe PDS manual has this to say about the PC required to run it:
In my case I’ve found a 486 PC with some ISA slots and 256MB of RAM. It has DOS 6.2 installed on a few 100 MB harddisk.
To install the PDS, I copied the above onto a floppy from my laptop using USB floppy drive, then on the DOS PC ran the “dopds.bat” command:
c:\> a:\dopds
This created the c:\pds directory then I can go to that directory and run pdsz80.exe.
On first run I got the error mentioned in the manual saying there must be 640K of memory. After fiddling around moving things out of AUTOEXEC.BAT and CONFIG.SYS (this wasn’t a fresh DOS install), eventually I ran MEMMAKER and that managed to free up ~620K of memory for applications, which seemed to be enough for pdsz80.exe to run.
Later in the PDS manual it recommends the following CONFIG.SYS settings:
BUFFERS=20
FILES=20Note: With no PC card installed, I just get a blank, blue screen, but with the PC card installed I get the following screen, so I’m seeing that as a sign the card is being detected ok.
The FUNCTION keys trigger alternative modes. This one made me smile – I can’t remember when I last saw a phone number in some software…
The PDS Editor Manual details how to use the PDS software. The modes are selected using the following FUNCTION keys:
- F1 [ASSEMBLE] Assembles the program in memory.
- F2 [SAVE/LOAD] Saves or loads all 8 files.
- F3 [GRAPHICS] Enters the graphics editor.
- F4 [MONITOR] Enters the monitor.
- F5 [CONFIGURE] Enters the PDS configuration system.
- F6 [PRINT] Prints files.
- F7 [HELP] Engages the help facility.
- F8 [REPEAT] Repeats search and replace functions.
- F9 [DISK] Enter the PDS disk system.
- F10 [FINISH] Eds current task.
The [CONTROL] and [SCROLL LOCK] keys together enable a dual-window view.
The [HELP] system is interesting. From the manual:
The system came with HELP files for the processor. There is a help.65 and help.z80 file in the “demos” area which I’ve yet to try (I haven’t worked out how to load it yet).
To load in a file of code, for example from the demo areas, CTRL-R inserts it at the current cursor position. I’ve not been able to use the DISK subsystem as apparently I don’t have anything that is XMSDOS formatted. I believe I can load in a file using CTRL-L from the DOS directories though.
There are many time-saving features implemented in the editor including things like header comment generation, automatic labelling, a special ESCape mode for advanced commands and macros, and not to mention an expanded assembly syntax that makes a bit more sense than the original.
There is a real sense of being written by programmers for programmers. It feels massively ahead of its time if I’m honest.
The Target Code
The target code is provided in source form only, as part of the “demo” code for the PC application. This is Z80 assembler (for the ZX Spectrum version) that needs to be assembled and loaded into ZX Spectrum memory.
The problem is that this uses the PDS assembler syntax, which isn’t the same as many standard (if there is such a thing) Z80 assembler syntax.
So this presents a problem. I need to generate a binary, on a tape, that can be loaded into the ZX Spectrum, but I have to find a way to do that from the PDS environment itself. On a 486 PC.
The code itself has, I believe, a possible answer. The comments at the start of the code states the following:
; The long PDS download software for the ZX-SPECTRUM
;
;This is the long download software for the Spectrum, it allows all the
;monitor commands except Analyze to work correctly and will allow you
;to assemble and download programs.
;It may be situated anywhere in memory. Note that it uses up two bytes
;of stack space, it uses the Sinclair stack, setup at the top of memory
;or where ever you do a CLEAR. It disables the interupts, so you may
;download over the system variables at 5C00h upwards.
;
; The code is exactly 344 bytes long
;
;When you first run the download software you should jump to label START,
;if you intend to enter it again then you should jump to MONITOR as it will
;already be setup correctly.
;
;
;
; Setup this ORG to point where you want the download software to be in
; memory. Note that this program as is, requires eight bytes before this
; address for a small 'return to basic program'
;
ORG 8000H ;This could go anywhere (best in fast memory >8000h)
;Ok, so far so good. Then there is the following at the end:
;
; End of the download software, now a small program to set the top of memory
; one byte below the download software, then reset the spectrum and return
; to basic so you may save out the download software using the following
; basic loader :
;
; 1 LOAD "" CODE:RANDOMISE USR start address
;
; Save this using either :
;
; SAVE "DLOADER" LINE 1 : SAVE "CODE" CODE startaddress,344
;
; or for microdrives :
;
; SAVE *"m";1;"DLOADER" LINE 1 : SAVE *"m";1;"CODE" CODE startaddress,344
;
;
ORG START-8 ;Put before download (so gets overwritten)
EXEC $ ;Execute code from here
DI
LD DE,START-1 ;Where 'top of memory' will be
XOR A
JP 11CBH ;Reset Spectrum, leaving download software
;
;
;
SEND COMPUTER1
ENDI believe this allows the PDS to assemble and download the monitor code, then save it out to storage using the recommended BASIC commands once the Spectrum resets after loading.
It uses two PDS “pseudo ops” – “EXEC” and “SEND” which are special PDS commands to set the execution address for the code and to instruct the PDS to download the code, in this case using the COMPUTER1 interface.
But to get to this point requires a working PDS system in the first place. So how does all this start? The PDS Z80 manual has this to say:
This code is provided to allow one to rebuild the monitor with a custom location and so on, and yes, it does indeed assume you already have a monitor program on tape to load into the Spectrum to get everything started… So therein lies the problem.
There are some online assemblers that will compile down to a ZX Spectrum TAP file, which is a sound file ready for loading onto a Spectrum, so if I can fiddle with the syntax I might be able to use one of those.
Here I hit some issues:
- https://beta.asm80.com/ This allows me to build to a HEX file or similar, but there is no way I can find to get this into a format I can get to a ZX Spectrum.
- https://clrhome.org/asm/ This has a “build to TAP” option, but I just couldn’t get the interface to work with the PDS code.
- https://k1.spdns.de/cgi-bin/zasm.cgi This again allows me to upload a source file and produce several outputs, but again no option for a ZX Spectrum load format.
The next option is a tool like https://github.com/retro-speccy/bin2tap which takes a binary file and produces a ZX Spectrum TAP file. But this once again is source code, so that itself is an entire side-quest I don’t really want to follow right now.
Finally, I just decided I might have to type the binary in by hand, so I’m focussing on the minimal downloader – z80.dl0 and using asm80.com. This appears to require the following changes to the source.
- All jump instruction shortcuts need expanding – e.g. JZ -> JP Z; JNZ -> JP NZ; JC -> JP C and so on.
- Jump instructions also need a comma adding – e.g. JZ LABEL -> JP Z, LABEL.
- All labels need a “:” adding – e.g. “START” becomes “START:”.
- The last block of “small program” has to be removed, as this can’t be assembled or built without the PDS itself.
This gives me the following source:
ORG 8000H ;This could go anywhere (best in fast memory >8000h)
;
STARTL: DI
LD A,255
OUT (127),A
OUT (63),A
LD A,63
OUT (127),A
LD A,255
OUT (95),A ;Setup the direction of the IO ports
OUT (95),A
LD D,64 ;Setup flags - Input from main computer
;
; Main loop
;
MAINLOOP: CALL GETBYTE ;Get 'command byte'
LD A,E
CP 180 ;Download code into aabb, len=ccdd
JP Z,DLOAD
CP 183 ;Select bank aa
JP Z,SBANK
CP 181 ;Execute code from aabb?
JP NZ,MAINLOOP ;Not recognised - keep looping.
;
; Function 181, Execute code from aabb
;
CALL GETBYTE
LD H,E ;Get address of routine
CALL GETBYTE
LD L,E
LD BC,MAINLOOP
PUSH BC ;Put return address on stack and jump to routine
JP (HL)
;
; Function 180, Download code into aaaa, length=bbbb
;
DLOAD: CALL GETBYTE
LD H,E
CALL GETBYTE
LD L,E ;Get start address
CALL GETBYTE
LD B,E
CALL GETBYTE
LD C,E ;Get length of code
;
DLOAD1: CALL GETBYTE
LD (HL),E ;Get bytes and store in RAM
INC HL
DEC BC
LD A,B ;Keep getting bytes
OR C
JP NZ,DLOAD1
JR MAINLOOP ;Go back into main download loop
;
; Function 183, select bank xx (This is different for each target computer)
;
SBANK: CALL GETBYTE
LD BC,7FFDH ;HL, BC and A may be corrupted here
OUT (C),E ;This will change banks on the speccy '128
JR MAINLOOP ;E is the bank data byte, D is not to be used!
;
; Get a byte from the main computer into E
;
GETBYTE: IN A,(63)
XOR D
RRCA
JP C,GETBYTE ;Wait for 'I've sent the byte'
IN A,(31)
LD E,A ;Get the byte into the E register
LD A,D
OUT (63),A ;Say 'I've got it!'
XOR 129
LD D,A ;Flip flags for next byte
RET
;This builds to the following HEX file:
:10800000F33EFFD37FD33F3E3FD37F3EFFD35FD3CB
:108010005F1640CD5A807BFEB4CA3380FEB7CA508B
:1080200080FEB5C21380CD5A8063CD5A806B011398
:1080300080C5E9CD5A8063CD5A806BCD5A8043CD3F
:108040005A804BCD5A8073230B78B1C2438018C33A
:10805000CD5A8001FD7FED5918B9DB3FAA0FDA5ADE
:0B80600080DB1F5F7AD33FEE8157C921
:00000001FFDecoding this, requires understanding the HEX record format, which is essentially:
:<LEN><ADDR><TYPE><DATA><CKSUM>
~First Line~
: Start
10 Length=16 bytes in this record
8000 Address=0x8000
00 Record type=00, which is Data
F33E FFD3 7FD3 3F3E 3FD3 7F3E FFD3 5FD3
CB Checksum
~Penultimate Line~
:
0B Length=11 bytes
8060 Address=0x8060
00 Record type=00, Data
80DB 1F5F 7AD3 3FEE 8157 C9
21 Checksum
~Last Line~
: 00 0000
01 Record Type=01, End of File
FF ChecksumThis can be translated into the following BASIC program for the ZX Spectrum which stores the assembly as a series of numbers in a DATA statement and loads it into memory (see chapter 26 of the original ZX Spectrum BASIC Programming book).
Unfortunately I don’t think I can enter them as HEX, so they have to be converted to decimal. I used the following python script on the binary version of the output (right click on the hex file in the online assembler and do HEX -> BIN).
with open("pdsdl0.bin", "rb") as file:
data = file.read()
for b in data:
print(",", b, end='')Pasting the resultant output into a BASIC program as a series of DATA statements gives me the following.
5 CLEAR 32760
10 LET a=32768
20 READ n: POKE a,n
30 LET a=a+1: GOTO 20
40 DATA 243, 62, 255, 211, 127, 211, 63, 62
45 DATA 63, 211, 127, 62, 255, 211, 95, 211
50 DATA 95, 22, 64, 205, 90, 128, 123, 254
55 DATA 180, 202, 51, 128, 254, 183, 202, 80
60 DATA 128, 254, 181, 194, 19, 128, 205, 90
65 DATA 128, 99, 205, 90, 128, 107, 1, 19
70 DATA 128, 197, 233, 205, 90, 128, 99, 205
75 DATA 90, 128, 107, 205, 90, 128, 67, 205
80 DATA 90, 128, 75, 205, 90, 128, 115, 35
85 DATA 11, 120, 177, 194, 67, 128, 24, 195
90 DATA 205, 90, 128, 1, 253, 127, 237, 89
95 DATA 24, 185, 219, 63, 170, 15, 218, 90
100 DATA 128, 219, 31, 95, 122, 211, 63, 238, 129, 87, 201
RUN
PRINT USR 32768At this point I can type it into the ZX Spectrum and hit RUN to load it and then PRINT USR 32768 to run it. The screen goes blank and the Spectrum is now waiting for commands from the PDS. In theory.
Back at the PDS end, I’ve tried the Monitor (F4) F(ill) command and I get “ERROR – The other computer is not receiving.”
If I load in one of the existing downloader programs (using CTRL-R) and attempt to assemble it (F1), I get a message “From 7FF8h to 8156h, exec=7FF8h. Download (Y/N)?” and upon selecting “Y” at this point everything hangs…
Update (July 2026) – This works! I’ve added in an additional CLEAR command at the start so don’t know if that makes a difference, or if I was just really, really careful to make sure I typed everything in correctly, but the above BASIC code does now work and I can use F(ill) as described in Part 6 and see data being written to the display!
Conclusion (for now)
So at this point, the things I know are:
- The PDS software is running on the PC and appears to be able to see the PC Card.
- The target card appears to be able to be seen from a ZX Spectrum direct OUT instructions to the Z80 PIO’s registers.
- It wasn’t working.
So the issues could be any of:
- The PC card is wrong somehow (e.g. pinouts to the cable).
- The Intel 8255 isn’t working properly on the PC card.
- The cable is wrong somehow (remember it appears to have a reversal of pins).
- The target card is wrong somehow (e.g. pinouts to the cable).
- The Z80 PIO isn’t working properly on the ZX Spectrum card.
- The ZX Spectrum target software was typed in wrong (I tried it twice though).
- The ZX Spectrum target software isn’t built correctly.
- The ZX Spectrum target software is not compatible with this version of the PC software/hardware.
I need to get some proper debugging on the link to try to figure out what might be going on.
Spoilers: It is now working (see update above and full details in Part 6).
Kevin
#ISA #pds #programmersDevelopmentSystem #zxSpectrum -
Just #Intel things. Would be fun to know why? Was it broken, or do they not want to pay the die cost going forward?
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[Перевод] Проектируем с нуля калькулятор на FPGA. Часть 6: CPU
← Четвёртая и пятая части Это самый длинный пост всей серии, потому что он посвящён главной части этого проекта — всё вращается вокруг CPU. Почему бы просто не взять готовый CPU? Кто-то может заявить: зачем заморачиваться проектированием собственного CPU? Есть куча маленьких хорошо задокументированных процессоров и дешёвых микроконтроллеров, способных исполнять прошивку калькулятора. Zilog Z80 не так сложно реализовать на FPGA, и я в этом уже убедился (проект A-Z80 , находящийся у меня на GitHub). Подойдёт и 6502. Маленький встраиваемый RISC тоже прекрасно справится с этой работой. Отвечу честно: это было бы не так интересно, потому что подобное уже много раз делали. Но есть и другие (более удобные для меня) причины. Наш калькулятор построен на BCD (двоично-десятичном коде),в котором каждый десятичный разряд хранится в отдельном 4-битном полубайте (ниббле). Это правильный выбор для калькулятора, и он определяет всё дальнейшее. Z80 (и другие стандартные CPU) работает на уровне байтов. Для индексации регистра мантиссы из 16 нибблов с ориентированным на байты процессором пришлось бы постоянно жонглировать сдвигами, масками и двумя нибблами на байт. На каждом шаге режимы адресации вступают в конфликт со схемой данных. Нам же нужен процессор, в котором 4 бита будут естественной единицей данных, где память адресуема по нибблам и где режимы адресации позволяют тривиально обходить мантиссу разряд за разрядом. Всего этого нет ни в одном CPU общего назначения, поэтому мы спроектируем собственный.
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Viele 🚗 🚚 🚗 treffen sich gerade auf der A1: Trier -> Köln/Koblenz, zwischen AK Wittlich und 1.8 km vor Flussbach und blockieren die #Autobahn.
Es könnte sein, dass sie heute die #EU-weit verpflichtende Installation eines intelligenten, übersteuerbaren Geschwindigkeitsassistenten in alle #Neufahrzeuge fordern. Das könnte langfristig die Zahl der #Verkehrstoten um 20% reduzieren. Viel weniger Autos hätten #Totalschaden. 🚗⚠️ #Verkehrssicherheit #ISA (Quelle: ETSC)
https://etsc.eu/wp-content/uploads/PIN-flash-report-36-Final.pdf -
Viele 🚗 🚚 🚗 treffen sich gerade auf der A1: Trier -> Köln/Koblenz, zwischen AK Wittlich und 1.8 km vor Flussbach und blockieren die #Autobahn.
Es könnte sein, dass sie heute die #EU-weit verpflichtende Installation eines intelligenten, übersteuerbaren Geschwindigkeitsassistenten in alle #Neufahrzeuge fordern. Das könnte langfristig die Zahl der #Verkehrstoten um 20% reduzieren. Viel weniger Autos hätten #Totalschaden. 🚗⚠️ #Verkehrssicherheit #ISA (Quelle: ETSC)
https://etsc.eu/wp-content/uploads/PIN-flash-report-36-Final.pdf -
Le Congrès s’apprête à rapprocher plus que jamais les armées américaine et israélienne
https://www.les-crises.fr/le-congres-s-apprete-a-rapprocher-plus-que-jamais-les-armees-americaine-et-israelienne/
Une nouvelle disposition permettrait de fusionner les complexes militaro-industriels américain et israélien, tout en les soustrayant davantage au regard du public. Source : Truthout, Ben FreemanTraduit par les lecteurs du site Les-Crises Un soldat israélien monte la garde entre les drapeaux israélien et américain dans un nouveau camp militaire lors d’un exercice conjoint avec l’unité […]
#Politique #Géopolitique #Isa #Israël -
Le Congrès s’apprête à rapprocher plus que jamais les armées américaine et israélienne
https://www.les-crises.fr/le-congres-s-apprete-a-rapprocher-plus-que-jamais-les-armees-americaine-et-israelienne/
Une nouvelle disposition permettrait de fusionner les complexes militaro-industriels américain et israélien, tout en les soustrayant davantage au regard du public. Source : Truthout, Ben FreemanTraduit par les lecteurs du site Les-Crises Un soldat israélien monte la garde entre les drapeaux israélien et américain dans un nouveau camp militaire lors d’un exercice conjoint avec l’unité […]
#Politique #Géopolitique #Isa #Israël -
Preaching against the virgin birth, using the Bible as evidence? That's a new one.
The Bible most definitely says Mary was a virgin when Gabriel, the archangel, visited her to declare she was chosen to give birth to the Son of God. He was called Emmanuel, meaning God with us, and named JESUS.
Matthew 1:18-23
Luke 1
Isaiah 7:14Even the Muslim Quran says Jesus (Isa) was born of the virgin Mary.
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RE: https://social.ahlroos.me/@yle_fi_bot/116706902699466534
<3 Kniif <3
Ollaan tunnettu Knipin kanssa ysäriltä asti, josta osan aikaa #Knipi oli naapurinsetä.
Vähän on kyllä ikävä aikaa, että häneen ja ihanaan frouvaansa tämän tästä törmäsi.
#musiikki #muusikko #kuvataide #taide #kulttuuri #taiteilija #elokuva #leffa #näyttelijä #malli #kulttuurielämä #isä #isäsuhde #isyys #kuolema #menetys #vanhemmat #vanhemmuus #muistot #lapsuusmuistot #musadontti
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RE: https://social.ahlroos.me/@yle_fi_bot/116706902699466534
<3 Kniif <3
Ollaan tunnettu Knipin kanssa ysäriltä asti, josta osan aikaa #Knipi oli naapurinsetä.
Vähän on kyllä ikävä aikaa, että häneen ja ihanaan frouvaansa tämän tästä törmäsi.
#musiikki #muusikko #kuvataide #taide #kulttuuri #taiteilija #elokuva #leffa #näyttelijä #malli #kulttuurielämä #isä #isäsuhde #isyys #kuolema #menetys #vanhemmat #vanhemmuus #muistot #lapsuusmuistot #musadontti
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I feel like overlapping FP and integer register file and ports may be better than overlapping FP with SIMD.
Because you kind of want scalar FP to be higher issue and lower latency that you need for SIMD float operations.
If you have 128-bit SIMD the goals are mostly aligned, but for >=256-bit sharing FP with SIMD becomes less attractive in my mind.This also isn't all that relevant if your integer execution isn't something like 6 wide or wider.
It also gives you have more control over FP32 and FP64. Maybe you put FP32 on all ALUs, but FP64 only on the ones that also support IMUL (if you can share that logic).
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I feel like overlapping FP and integer register file and ports may be better than overlapping FP with SIMD.
Because you kind of want scalar FP to be higher issue and lower latency that you need for SIMD float operations.
If you have 128-bit SIMD the goals are mostly aligned, but for >=256-bit sharing FP with SIMD becomes less attractive in my mind.This also isn't all that relevant if your integer execution isn't something like 6 wide or wider.
It also gives you have more control over FP32 and FP64. Maybe you put FP32 on all ALUs, but FP64 only on the ones that also support IMUL (if you can share that logic).
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Happy Birthday, #Ethernet!
Man, this article took me down memory lane lol. My networking days started with #10Base2, T-connectors, #ISA NICs, #tokenring topologies, and #Novell's IPX/SPX! #Thicknet was already old tech when I got into it in the mid to late 1980's. But I did learn about it at my local library! I wasn't even 10 yet!
Can you even imagine what a #terabit looks like? My past self wouldn't have even thought that was possible in his lifetime lol.
Thank you Bob Metcalfe! Our world literally would not be what it is without your invention.
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Happy Birthday, #Ethernet!
Man, this article took me down memory lane lol. My networking days started with #10Base2, T-connectors, #ISA NICs, #tokenring topologies, and #Novell's IPX/SPX! #Thicknet was already old tech when I got into it in the mid to late 1980's. But I did learn about it at my local library! I wasn't even 10 yet!
Can you even imagine what a #terabit looks like? My past self wouldn't have even thought that was possible in his lifetime lol.
Thank you Bob Metcalfe! Our world literally would not be what it is without your invention.
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Viele 🚗 🚚 🚗 treffen sich gerade auf der A3: Nürnberg -> Passau, zwischen 3.0 km hinter Spitzig Berg und 3.6 km vor Kühberg und blockieren die #Autobahn.
Es könnte sein, dass sie heute die #EU-weit verpflichtende Installation eines intelligenten, übersteuerbaren Geschwindigkeitsassistenten in alle #Neufahrzeuge fordern. Das könnte langfristig die Zahl der #Verkehrstoten um 20% reduzieren. Viel weniger Autos hätten #Totalschaden. 🚗⚠️ #Verkehrssicherheit #ISA (Quelle: ETSC)
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Viele 🚗 🚚 🚗 treffen sich gerade auf der A3: Nürnberg -> Passau, zwischen 3.0 km hinter Spitzig Berg und 3.6 km vor Kühberg und blockieren die #Autobahn.
Es könnte sein, dass sie heute die #EU-weit verpflichtende Installation eines intelligenten, übersteuerbaren Geschwindigkeitsassistenten in alle #Neufahrzeuge fordern. Das könnte langfristig die Zahl der #Verkehrstoten um 20% reduzieren. Viel weniger Autos hätten #Totalschaden. 🚗⚠️ #Verkehrssicherheit #ISA (Quelle: ETSC)
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I loved ❤️ the TV series:
“Halt And Catch Fire”, Scott Robinson (https://unstack.io/halt-and-catch-fire).
Via HN: https://news.ycombinator.com/item?id=48162468
#ComputerHistory #CPU #Hardware #RetroComputing #ISA #HCF #HaltAndCatchFire #TV #TVSeries #IBM #Motorola
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Viele 🚗 🚚 🚗 treffen sich gerade auf der A3: Nürnberg -> Passau, zwischen 3.0 km hinter Spitzig Berg und 3.6 km vor Kühberg und blockieren die #Autobahn.
Es könnte sein, dass sie heute die #EU-weit verpflichtende Installation eines intelligenten, übersteuerbaren Geschwindigkeitsassistenten in alle #Neufahrzeuge fordern. Das könnte langfristig die Zahl der #Verkehrstoten um 20% reduzieren. Viel weniger Autos hätten #Totalschaden. 🚗⚠️ #Verkehrssicherheit #ISA (Quelle: ETSC)
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"Thanks bro, Isa mad helpful in these trying times"
https://piefed.social/c/historymemes/p/2059898/thanks-bro-isa-mad-helpful-in-these-trying-times
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PDS – the Programmers Development System – Part 2
This series of posts looks at the Programmers Development System (PDS).
- Part 1 – Introduction, background and some initial reverse engineering.
- Part 2 – A closer look at the PC ISA Interface card.
Having now got a bit of an idea of how the PDS appears to work in my previous post (PDS – the Programmers Development System) I’m now taking another look at the PC interface and starting to think about the possibility of recreating the system.
The PC Interface
Having decided I couldn’t rely on the schematic on the CPC wiki, I’ve taken the printout-versions of the PCB traces and started tracing them through to see what is really going on. It was greatly helped by the PCB view that can be found here: https://lemmings.info/pds-programmers-development-system/
Of course, I am assuming here that the remade PC card does actually work.
It turns out the ISA to Intel 8255 part was fine, including the address decoding, but the three 8255 IO ports, through the octal line buffers, to the two PDS links are fundamentally missing some key links.
Essentially the three 74LS244s are configured for half in A->Y form and half in Y->A. The three IO ports (PORT A, B, C) are also split in half. This means that most of this circuit is working in 4-bit chunks.
The high level linkages are shown below.
So here we can see how the A halves of each of the 244s handles OUTPUT and the B halves handle INPUT. We can also see that U5 (sticking with the original schematic numbering for now) handles the control signals, U4 is D4-7 and U3 is D0-3. PORTC drives U5 and thus also handles all control signals.
We can also see that the data lines are now fully bidirectionally connected so that each can be connected to an OUTPUT or an INPUT depending on the state of the PC2 line. PORTB handles the OUTPUT and PORTA is the input.
The control signals are still mirrored as determined in the first part, but now we can see that some are OUTPUTs and some are INPUTs. The mappings from PC0-7 through to the link pins is shown below (note I’ve reverted to using the same PDS connector pin numbers as the ZX Spectrum schematic in the diagram above and table below).
PIODirectionLink 1 PinLink 2 PinPC0OUT313PC1OUT133PC2OUT1111PC3OUT99PC4IN515PC5IN155PC6IN7N/CPC7INN/C7There are two swapped pairs of connections, two common, and one unique to each.
As mentioned previously, the ZX Spectrum interface does not connect to pins 9,11,13,15 so that implies to me that it would not work out of link 2 without remapping in the software for the alternative pinout.
From working through the ZX Spectrum monitor code in part 1, we can infer the following functions:
- Pin 3 (OUT): PC to Target CLOCK
- Pin 5 (IN): Target to PC CLOCK/ACK
We can also note the following:
- Pin 11 (OUT): Direction based on PC2. HIGH = PC to Target; LOW = Target to PC
From this point I can now fully recreate the schematic and start to think about recreating the PCB.
The PC Hardware
One slight sticking point in remaking the PCB was getting useful dimensions for an XT era ISA card. Two useful references I found were:
- The ISA Spec can be found as part of the PC XT Technical Reference: https://bitsavers.org/pdf/ibm/pc/xt/6361459_PC_XT_Technical_Reference_Apr84.pdf
- Researched 8-bit ISA card dimensions: https://www.andavno.com/?p=87
The actual spec wasn’t massively useful to me. I don’t know if the ends of cards was slightly different in PC XT systems, but it doesn’t seem to match the photos of the PDS PC card. The second link was very well researched and complete however, so I went with that.
One compromise though was trying to keep the card within a 100x100mm footprint, so I’ve not extended completely to what I believe will be long enough to have an end plate.
The Schematic
The updated schematic is shown above. I’ve added a few things I’d expect to see on a modern design – additional 100nF capacitors (one for each IC), and a resistor network to pull up all unused inputs to the 74LS04.
I originally went with the ZX Spectrum version of the 16-way connector, but then when it came to assigning footprints, to get a right-angled IDC connector meant pin one was now in the wrong place, so I had to revert to the alternative pin numbering as per the original schematic.
The PCB
I’ve followed the original layout used on the PC card remake as far as possible, reasoning that the person who did this almost certainly knows a lot more about electronics than I do.
One thing I wasn’t sure about was a GND fill. I initially created a fill zone, but then decided I’d follow the original lead and use explicit GND connections. If someone advises that a fill will be better then it is pretty trivial to add in.
Other points to note:
- A already mentioned I’ve kept this within the 100x100mm footprint. This leaves two unknowns: will it be tall enough to be useful; and will it extend to the edge of a PC case?
- The two connectors extend beyond the edge of the PCB, so they hopefully will be available at the edge of a PC.
- The dimensions are such that more of the PCB is off to the right compared to the photos of the remade board I’ve seen.
This will do for now, but I think it is highly likely there will need to be some physical adjustments for this to be usable.
Conclusion
I believe I’ve got an accurate schematic for the board based on the photos available and I now have design for a candidate PCB. The problem is that I don’t know anything about what the software is expecting when it drives the Intel 8255 to work the PDS interface.
There is also the small matter of needing an ISA bus in a PC…
I’m hoping to get these boards published somewhere but right now, I’m not clear what the licensing issues would be. These boards are not available anymore, but at some point this was a company’s IPR.
For now, I’ll keep blogging observations and see what the interest is.
Next up will be some remake of the target PCBs.
Kevin
#intel8255 #ISA #pcXt #pds #programmersDevelopmentSystem
