#epoc16 — Public Fediverse posts

THE JOYS OF SERIAL COMMUNICATION!

#psion3 #sibo #epoc16 #mclink #rs232

PS:

Changing "main()" to "int main()" will already cause the compiler to barf.

#psion3 #sibo #epoc16 #smallc

Here is the code in the file "HELLO.C". I'm afraid it is rather non-standard.

/* Take a look at win.c for full details about
using #link and #run etc..
*/

#link "-om:\img\hello.img hello.o stdio.o"
#run "m:\img\hello.img"

#include <stdio.h>

main()
{
printf("Hello world\n\r");
fgetc(stdin);
exit(0);
}

#smallc #psion3 #sibo #epoc16

Here are my efforts to document compiling C-Code with Small C to an IMG-File on the Psion 3c itself.
Steps:
1. Scrolling through the C-Code
2. Compiling with <Psion>+T
3. Switching to the IMG-Files launcher
4. Running the IMG-File itself and terminating with <ESC>

I apologise for the lousy quality of the the video.

#retrocomputing #epoc16 #sibo #psion3 #smallc

/cc @thelastpsion

Things I'd like to achieve next year

...with zero pressure - just stuff I'd like to do if I get the chance

• Get as many of the #Psion SIBO C SDK apps rewritten as possible. I really enjoy using #FreePascal for this! It's vastly underrated for writing cross-platform CLI apps.
• Make some code run on #EPOC16 from a tiny/toy #compiler of my own. Not an entire C compiler, just something where I've generated some 8086 (or NEC V30) assembly from something very basic that actually runs, including implementing the TopSpeed calling convention.
• Work out how the #MAME debugger works so that I can add 4MB RAM support to EPOC16. Maybe learn some things about the internals of EPOC16 along the way. Eventually write this updated EPOC16 ROM to flash and get it running on real hardware.
• Make a #PsiDrive PCB that can write to flash drives. Just needs a +16V boost converter added to the board.
• Get an #RP2350 to pretend to be a small Psion SSD, using the on-die RAM and PIO. Bonus if it uses a battery. Extra bonus if it can write to external RAM or Flash.
• Move #libsibo away from the Arduino libraries and over to the Pico SDK. This just feels like the right move, but means I'll need to learn cmake as well.
• Learn how to write good unit tests. It's not a problem with learning frameworks - both fptest and fpcunit are simple enough. My brain is freezing when trying to decide on what to test and why. I know my code will improve once I've grasped this.

There are a lot of moving parts to all of these. Some need me to learn multiple sub-skills, such as 8086 assembly. Like I said, this isn't a list of Things Alex Must Get Done Next Year. I'd be happy if I achieved just one of them.

I'm curious... Which one of these would you like to see the most?

#retrocomputing

Time for another poll:

#psion #psion3 #psion5 #epoc16 #epoc32

Some #Psion news! #plptools, the open source suite of programs for transferring files to and from #EPOC16 and #EPOC32 devices, has some additional maintainers: @captfab, @jbmorley ... and me!

We're looking into how we can take the project into the future. We do have some ideas, but we're taking a considered approach to future development.

plptools currently runs on Linux and macOS (and possibly FreeBSD, NetBSD, Solaris, AIX and HP-UX, although these haven't been tested in a while). I've started work on porting it to #HaikuOS.

The repo has been moved to a new GitHub organisation, which you can find here. https://github.com/plptools/plptools

#retrocomputing

If anyone fancies following in my footsteps with #EPOC16 hackery, I've released my updates to #EDisAsm as 0.0.6. First update in a couple of years!

https://github.com/thelastpsion/edisasm/releases/tag/0.0.6

#Psion #retrocomputing

Some success with the 4MB #Psion 3mx!

I've been able to write directly to a page of RAM in the upper 2MB of memory, using #EDisAsm. I modified one of the memory-dumping assembly routines to basically go in the opposite direction. It writes 16 bytes to bank 0x6000, page 0x20. Then I dumped that to a file.

It worked! There's no corruption, and I can't see it mirrored anywhere. Using this basic test, we can pretty safely say that ASIC9MX is able to address the extra RAM (like the SDK says), and that the second chip is soldered correctly.

However, this doesn't explain why #EPOC16 doesn't like it. To recap, although EPOC16 reports that it has 4MB RAM, the ramdrive (M:) is inaccessible - apps report that the "media is corrupted", and the OS says it's unformatted. Any attempt to format the ramdrive fails silently.

The current guess is that the ramdrive "driver" can't handle more than 2MB RAM. It might be just the formatting routine, but it could be the ramdrive filesystem can't handle it. However, there might be a hard limit on pointers. This could be a bigger issue: the ramdrive in EPOC16 resizes dynamically, so the ramdrive "driver" and the filesystem's pointers would need to be able to handle the bigger filesystem size.

Unfortunately, this filesystem is undocumented - Psion never expected anyone to need to fiddle with it. Fortunately, EDisAsm can dump all memory, so it would be possible to analyse it. Dump a freshly booted 2MB 3mx, add a file, dump it again, delete a file, dump it again...

If it turns out that this is the case, it might be necessary to create a custom EPOC16 ROM. This would require a few things: working out how to modify the driver (and anything else) successfully, putting together a new EPOC16 image with the be driver, and a 3mx that's been modded to take flash. Bearing in mind that no EPOC16 source has been unearthed.

In conclusion, definitely progress, but there's still a long way to go.

#retrocomputing

Some of you might vaguely remember that I have a mildly modified #Psion Series 3mx. It's got an extra 2MB RAM, bringing it to 4MB. One snag - it doesn't work.

When I last left it (a few months back), #EPOC16 couldn't see the extra 2MB RAM - the OS was saying the machine only had 2MB RAM. However, #EDisAsm (the EPOC16 disassembly/debugging/dumping tool) was able to see and dump the upper 2MB of the 4MB RAM. This means that ASIC9MX's NRAS0 and NRAS1 are clearly working, acting as chip selects. Something else was wrong.

Yesterday, I decided to revisit it. I discovered that pin D1 on the second RAM chip wasn't making contact with the pad. A quick reflow of all the pins on that chip and... a familiar error!

"Media is corrupt"

So now EPOC16 can see the second chip, but it doesn't like something about it. Last time this happened, it was because I'd put in the wrong type of RAM chip (10 rows by 10 columns, rather than 12 rows by 8 columns), so the address lines were messed up. This time I know it's the right chip, because it's identical to the first RAM chip. And the first chip is fine, because if it wasn't then the machine wouldn't boot.

I loaded EDisAsm onto an SSD and dumped the entire 4MB RAM over RS232 to see if I can see any patterns in the higher banks of memory (0x20 to 0x3F). I've also dumped the RAM from a normal 2MB 3mx to see if there are any clues.

Of course, the chip could also be faulty, causing the corruption. (I have spares.) It could be that there's another data pin not connected properly (I did re-flow all the pins and check continuity, but you never know). Alternatively, EPOC16 might just not like seeing more than 2MB RAM, even if ASIC9MX supports it, meaning it's never going to work without some software hackery.

I'm going to leave it again for now as I have $dayjob stuff to be getting on with. I don't know whether to feel encouraged or discouraged by this, but I guess it's progress of sorts.

#retrocomputing #16bit

So, I'm at a crossroads. I'm contemplating:

• Plough on with #CTRAN unit tests and refactor in #ObjectPascal and #NeoVim, and the write-up
• Try rewriting a different #Psion SIBO SDK tool in #ObjectPascal and #NeoVim
• Try a new project that's been on my mind for a long time, in C but use #VSCode

I feel like I'm slowing down with CTRAN development. After all, it "works"... but it's not "right."

The write-up is just a hard slog.

Moving on to a new tool might give me some inspiration on how to improve CTRAN. But I don't want to leave a trail of mostly-finished projects in my wake.

The C project is a bit special to me. It's also something people might actually use - unusual for one of my projects! It's for Psion #EPOC16 and would enable a huge number of old games to run on the Series 3a/c/mx.

I was hoping to use NeoVim, but with clangd being awkward, I'd have to use VS Code.

@thelastpsion

Are you aware of this site?

https://psion.gtkc.net/src.doc.ic-mirror/development/

In particular:
* Small C for EPOC16 (s3c111.zip)
* Forth for EPOC16 (forth129.zip)

Would be interested in any experiences.

(Why do I keep writing "EPIC16"?)

#retrocomputing #sibo #epoc16

Someone asked me some questions on the #Psion Series 3, so I thought I'd post my response here in case anyone else is interested. #LongRead

Emulator

You've got two options. The first is the original "emulators" written by Psion, S3AEMUL.EXE and S3CEMUL.EXE. They both run in DOS and emulate the 3a and 3c. But they're less of an emulator than a runtime environment for #EPOC16 (the OS). There's good and bad to this. You can run S3AEMUL and S3CEMUL straight in #DOSBox and it will talk to your host OS's filesystem (Windows, Linux, macOS, whatever). You need to map an M: drive in DOSBox for the internal storage, but once that's done you can copy files straight into that folder on your host OS and run them in the emulators. The downside is that it's not true hardware emulation. You won't get a good judge of the speed of a real device, and some syscalls aren't implemented so will fail or crash the #emulator. They're bundled with the SDK (see below).

The alternative is #MAME. This is the closest to proper hardware emulation you're going to find. You can either dump your own ROMs using a tool called #EDisAsm, or you can find them in the usual MAME ROM repos. The one thing that is notably missing is RS232 emulation from the later models, because we haven't been able to find any documentation on the silicon, but it's working fine with the 3a.

Toolchain

At the moment you have only one option - the Psion SIBO C SDK with the #TopSpeed C Compiler. You're going to need DOSBox (I personally prefer DOSBox Staging). It's all available on the Internet Archive in one easy download, including all the documentation you will need.

https://archive.org/details/psion-sibo-c-sdk

From there, you have a few libraries you can use. There CLIB, which is a pure ANSI C implementation, designed to easily port apps - don't use it, it's slow and you'll be missing a lot of features. Then there's PLIB, which is Psion's C dialect - very nice to use, and you can put together a C app pretty quickly. Finally, there's OLIB, which is Psion's proprietary OO C - it feels very clunky, but once you get over that it can be very powerful.

EPOC16 apps are restricted to a very pure version of the small memory model, but you can split code up into libraries known as DYLs.

In the past I've written code using VS Code, which can be made to play nicely with the SDK's header files. I've not got it working with NeoVim and clangd yet, but it should be possible with cmake.

The SDK comes with a debugger (SDBG.EXE), a DOS GUI app. If you run SDBG.EXE in DOSBox Staging, run the Psion3a MAME emulation, and enable RS232 over TCP on both, you can use SDBG to send apps to MAME. If you enable symbols, you can step through the code. It's rudimentary by modern standards, but it works pretty well.

I say "at the moment" because I'm slowly rewriting the tools in the SDK. I already have a new working version of #CTRAN, the preprocessor for Psion OO C, but I'm a long way from a compiler. There have been efforts to coax gcc into compiling for SIBO/EPOC16, but I think they have stalled for now.

If you want some examples of EPOC16 C and OO C code, take a look at these:
https://github.com/thelastpsion/edisasm
https://github.com/thelastpsion/pyramid
https://github.com/thelastpsion/nfsc
https://github.com/nickmat/Psion3-Wari
https://github.com/nickmat/Psion3-Vector

Device

The 3mx is the best choice. It's significantly faster than the earlier models (27.6 MHz vs 7.6 MHz), has a switchable backlight, the fastest RS232 and the best version of EPOC16. I "daily drive" one for journalling, adventure games, and a few other small tasks. After that I'd say the 3c (beware - they were covered in soft-touch rubber, so will need cleaning) and the 2MB 3a. The latter is the most common. Most 3c units came with a backlight, except for the early UK ones. The 3a doesn't. Arguably the non-backlit screens have better contrast so you don't need the backlight so much in lower light, but the backlight has obvious benefits.

#RetroComputing #RetroDev #16bit

REPOST (JAN 2024): My first thoughts on #Psion's dialect of Object Oriented C for the Series 3 and related portable computers.

Includes the JPI/Clarion #TopSpeed #compiler, a proprietary preprocessor, the Eiffel programming language, and a handful of calling conventions.

Also, did somebody say Objective-C?

This is an old blog post from the beginning of the year. If you've been following my journey in recreating #CTRAN, this was written a week before I decided to take the plunge.

https://hackaday.io/project/161291-the-last-psion/log/226441-beginning-olib-an-entirely-uneducated-look-at-psions-proprietary-object-oriented-c

(Yes, I did say in the article that I definitely wouldn't be writing a compiler. I did say that.)

#RetroComputing #EPOC16 #CDECL #Clarion #TopSpeed #TopSpeedC #RetroProgramming #RetroDev #Smalltalk #ObjectPascal #preprocessor #Eiffel #OOP #ObjectiveC #compilers #ObjectOriented

Here's something I wish would be open sourced.

The #TopSpeed C #compiler is an integral part of the #Psion SIBO C SDK.

Old timers might remember JPI as a group of developers who left #Borland in 1987, after Borland decided not to use the team's new compiler technology. They took their code with them, and it became the TopSpeed compiler.

From what I gather, the TopSpeed compiler IP is now owned by #SoftVelocity, the company who now also owns Clarion. I emailed them about 6 years ago, asking them if they would consider open sourcing the compiler code. I got no response, which I guess is to be expected.

I even found someone who had a copy of the source code (written in Modula-2), but they understandably wouldn't give it to me without the IP owner's approval.

This is the situation with so many bits of software (including the SIBO C SDK tools) from this time. We are lucky that copies of the applications still exist, otherwise the job of building C software for #EPOC16 would be significantly more difficult. But it is likely that the original source code, along with many other codebases, will disappear thanks to copyright laws that don't support digital preservation.

#retrocomputing #vintagecomputing #digipres

@thelastpsion
@inlovewithpda

Does anyone know what an error/exit code 80 is in #epoc16?

Thanks in advance and please boost for a wider audience!

#sibo #followerpower #epoc16 #boost

Upcoming projects:

⏸️ Learn #Psion's proprietary 16-bit OO C.
⏸️ Rewrite more of the SIBO SDK.
⏸️ Learn about designing #compilers and #assemblers.
⏸️ New version of #PsiDrive PCB.
⏸️ Vine: A new #FOSS #EPOC16 word processor aimed at writers/authors, with Vim motions and #AsciiDoc compatibility.
⏸️ Converting the Psion SIBO C SDK to AsciiDoc.
⏸️ #fefstool: Like #mtools but for #Psion Flash (FEFS) volumes.
⏸️ #MAME null modem mod, so that it can talk properly to #DOSBox.
⏸️ psion.info redux.
⏸️ More docs!

Projects waiting in the wings:

- Learning #Psion's proprietary 16-bit OO C. (It's what drove me to start working on CTRAN.) Also leads on to...
- Vine: A new #FOSS #EPOC16 word processor aimed at writers/authors, with #AsciiDoc compatibility. Plus new associated libraries and tools.
- Converting the Psion SIBO C SDK to AsciiDoc.
- #fefstool: Like #mtools, but for #Psion Flash (FEFS) volumes.
- #MAME null modem mod, so that it can talk properly to #DOSBox.
- Re-do psion.info.
- More docs!

@thelastpsion

It works now. Reasons:
1. Stupid brain fart (renamed wrong var)
2. Allocated too much initial memory

Must reprimand myself: this shouldn't have taken this much time.

#scheme #sibo #epoc16

Does anyone know how to make sense of this error? @thelastpsion ?

Thanks in advance.

#psion3 #sibo #epoc16

ICYMI: My first thoughts on #Psion's dialect of Object Oriented C for the Series 3 and related portable computers.

Includes the JPI/Clarion TopSpeed compiler, a proprietary preprocessor, the Eiffel programming language, and a handful of calling conventions.

Also, did somebody say Objective-C?

https://hackaday.io/project/161291-the-last-psion/log/226441-beginning-olib-an-entirely-uneducated-look-at-psions-proprietary-object-oriented-c

#RetroComputing #EPOC16 #CDECL #Clarion #TopSpeed #TopSpeedC #RetroProgramming #RetroDev #Smalltalk #ObjectPascal #preprocessor #Eiffel #OOP #ObjectiveC

A summary of my first impressions of #Psion's object oriented ecosystem for #EPOC16.

TL;DR: It feels janky, but I'm also a noob. Plus what about Objective-C?

I'm certain there's loads that I've missed with this. Do feel free to comment with constructive information.

#retrocomputing #retrodev #ObjectOriented #OOP #OO #ObjectiveC #programming #16bit #oldtech #smalltalk #epoc #psion3

https://hackaday.io/project/161291-the-last-psion/log/226441-beginning-olib-an-entirely-uneducated-look-at-psions-proprietary-object-oriented-c

Looking through some #Psion C code, I've seen `CDECL` a few times. Being a noob, I didn't know what they were or why they were there.

So, looking at Wikipedia...

#CDECL is a "caller clean-up" calling convention using the stack. This is pretty common in the x86 world, but is explicitly mentioned in Psion code. Why?

#TopSpeed C uses its own "callee clean-up" calling convention, using registers for the first 4 int parameters, which #EPOC16 really likes.

https://en.wikipedia.org/wiki/X86_calling_conventions

#RetroComputing

I've just remembered that the source for Vector - a CAD app for #EPOC16 - is on GitHub, and it's completely written in #Psion's OO C (plus some #MASM code).

I believe this is currently the only EPOC16 HWIM (Psion's OO graphics library) app whose source code has been released.

If you're following along at home, the code is in the link below.

https://github.com/nickmat/Psion3-Vector

#RetroComputing #RetroDev

Now that the TopSpeed TechKit with its #assembler is out in the world, I'm considering porting the #TASM and #MASM code in one or two of the open source #EPOC16 apps over to TSASM.

Hardly an urgent project, but it would mean that the apps could be built with one #compiler ecosystem with a single project file.

Of course, the code would still be restricted to the #16bit #DOS world, but it's no worse off than we already are in #Psion land.

#DOSBox #RetroDev #RetroComputing

Reading through the first manual in the SDK has reminded me what the "pure small memory model" is.

The ES register is never corrupted (DS=ES=SS).

#TopSpeed C implemented this, which was one of the main reasons why #Psion used it for the SDK.

I've heard that it's possible to implement this with #Borland C (and maybe #Watcom?), but I don't know how.

#16bit #retrocomputing #epoc16 #x86

I'll also be making a "2.21" with a few fixes, such as checking for includes properly.

I'm going to boldly say that my 2.21 version is the one you should use, but of course I'll distribute the older versions. I've definitely had projects that will compile with 2.00 but not with 2.20. I think these projects are more likely to compile with 2.21.

#Psion #epoc16 #psion3 #retrodev #retrocomputing

#Psion poll!

I'm going to make a video about how to install the SIBO C SDK in #DOSBox, so that people can compile apps for #EPOC16 computers (Series 3/3a/3c/3mx, Siena, Workabout, MC range).

If you are one of the tiny number of people who might be interested in using this, which modern OS do you use?

I want to know so that I can tailor the tutorial.

#retrocomputing #Psion3 #Psion3a

Wrote up a summary of the past year on Hackaday IO (@hackaday) because it was rattling around in my brain.

OK, *now* I'm going to rest.

#psion #retrocomputing #EDisAsm #sibolib #mame #PsiDrive #epoc16 #pda #vintagecomputing #retrodev #retrospective

https://hackaday.io/project/161291-the-last-psion/log/222163-a-long-overdue-update-pcbs-emulators-and-more

Anyone remember the Graphic Adventure Creator?

Originally made for the #Amstrad #CPC, my experience of it was from a #YourSinclair covertape.

Anyway, it's been on my list to attempt porting it to #Psion #EPOC16 for ages. It's not top priority, but the machine is perfectly designed for playing #textadventure games (see @root42's escapades with #Infocom).

Be great if it could decompile and play old games, too.

#retrocomputing #Psion3 #adventure

https://en.wikipedia.org/wiki/Graphic_Adventure_Creator
https://gac.interface1.net/

Started to build up a framework of files to supplement the #Psion SIBO C SDK for modern compilation.

First one... A half-decent gitignore file.

https://github.com/PocketNerdIO/edisasm/blob/main/.gitignore

It would be half the length if DOSBox Staging generated lower-case files by default.

#RetroComputing #RetroDev #EPOC16 #EDisAsm #git

Trying to give #EDisAsm a proper help menu, which requires compiling a resource (.RSC) file.

After much faffing, I've got compiled a basic .RSC file, and added its .RSG (header) file to the project. All compiled OK. Copied the app and .RSC to the DOS #EPOC16 emulator and...

DOES ANYONE REMEMBER HOW TO DO THIS?

I'm currently trawling through old code and the SDK docs.

#RetroComputing #RetroDev #Psion

Today, I'm getting distracted, trying to compile Elvis (an old #Vi spin-off) for #Psion #EPOC16.

Bearing in mind I'm running the original toolchain that this was developed with, this should Just Work™️. However... ERROR.

There are no instructions for compilation, so I don't know if there's a special order I need to do things in.

#RetroComputing #RetroDev #TopSpeedC #Vim

I'll write some proper instructions soon about how to make a small FAT volume with mtools.

In the meantime, go download the latest version of MAME with the #Psion #SIBO #emulator and use #EDisAsm to dump #EPOC16 #ROMs!

#RetroComputing

Found a way to get files on to the #MAME #Psion #SIBO #emulator without building any new tools!

#EPOC16 can read FAT volumes. So... mtools!

1. Make an empty file of, say, 2MB.
2. Use mtools to "format" it with FAT.
3. Use mtools to make directories in it and copy files into it.
4. Point MAME at the image.

Mtools is available for pretty much every Linux distro. And there's a version for Win32, too: https://github.com/foone/mtools_win32/releases/tag/4.0.23

Here's #EDisAsm 0.0.5 running on an emulated 3mx.

#RetroComputing

#EDisAsm v0.0.5 is out!

A few new features and fixes, but most importantly it now detects screen size.

This means it's no longer restricted to 3a/c/mx - most features now work properly on the #Siena, #Workabout 1 and Workabout mx!

ROM, RAM and SSD dumping are working on all #Psion ASIC9 machines.

And that dumping feature might be quite useful to people soon...

#RetroComputing #RetroDev #oldtech #16bit #epoc16 #epoc

https://github.com/PocketNerdIO/edisasm

Did you write code for #Psion machines in the #80s and #90s?

We're calling for you to open source your code!

I'm working with a group of enthusiasts, building a library of information about the SIBO/EPOC16 platform. Your old code could give valuable insight, as well as encourage people to write new code.

We're especially interested in old C and #x86 #assembly.

Upload it to your public repository of choice, and set it free!

#retrocomputing #retrodev #16bit #pda #laptop #epoc16 #sibo #oldcode

Did you write code for #Psion machines in the #80s and #90s?

We're calling for you to open source your code!

I'm working with a group of enthusiasts, building a library of information about the SIBO/EPOC16 platform. Your old code could give valuable insight, as well as encourage people to write new code.

We're especially interested in old C and #x86 #assembly.

Upload it to your public repository of choice, and set it free!

#retrocomputing #retrodev #16bit #pda #laptop #epoc16 #sibo #oldcode

Did you write code for #Psion machines in the #80s and #90s?

We're calling for you to open source your code!

I'm working with a group of enthusiasts, building a library of information about the SIBO/EPOC16 platform. Your old code could give valuable insight, as well as encourage people to write new code.

We're especially interested in old C and #x86 #assembly.

Upload it to your public repository of choice, and set it free!

#retrocomputing #retrodev #16bit #pda #laptop #epoc16 #sibo #oldcode

Did you write code for #Psion machines in the #80s and #90s?

We're calling for you to open source your code!

I'm working with a group of enthusiasts, building a library of information about the SIBO/EPOC16 platform. Your old code could give valuable insight, as well as encourage people to write new code.

We're especially interested in old C and #x86 #assembly.

Upload it to your public repository of choice, and set it free!

#retrocomputing #retrodev #16bit #pda #laptop #epoc16 #sibo #oldcode

Did you write code for #Psion machines in the #80s and #90s?

We're calling for you to open source your code!

I'm working with a group of enthusiasts, building a library of information about the SIBO/EPOC16 platform. Your old code could give valuable insight, as well as encourage people to write new code.

We're especially interested in old C and #x86 #assembly.

Upload it to your public repository of choice, and set it free!

#retrocomputing #retrodev #16bit #pda #laptop #epoc16 #sibo #oldcode