PETTESTER Pro / PET One ROM diagnostics

This repository contains the RetroRescues adaptation of the Commodore PET/CBM PETTESTER ROM, plus a 2 KB boot menu for the RP2350 based One ROM emulator from piers.rocks (https://onerom.org/).

The menu is designed to use the One ROM host-control plugin and the rom-bus-control-protocol so a PET can choose between several EDIT-socket diagnostic ROM images at boot.

Release ROMs

The current precompiled 50 Hz ROM images are in roms/:

File	Purpose
roms/petmenu2k.bin	Slot 0 boot menu. Checks One ROM non-volatile boot preference, allows key/timer menu selection, then boots the selected slot.
roms/pettester.bin	RetroRescues V6 PETTESTER build. Adds startup beep, simple 40/80 column VRAM detection, CRT warmup delay, and compact IEEE-488 self-test output.
roms/petieee2k.bin	Standalone IEEE-488/GPIB diagnostic ROM with clearer per-line status display.
roms/petromid2k.bin	Standalone ROM CRC16 identifier. Computes CRCs for CPU-visible PET ROM ranges and names known matches from common PET ROM sets.
roms/diagclipedit2k.bin	Experimental EDIT-ROM wrapper for the Commodore Diagnostic Clip RAM-resident test body.

The matching sources are in src/. Most implementation notes are in the ASM files. More detailed notes are in docs/, including the menu behavior, standalone diagnostics, and IEEE test translation.

TL;DR: One ROM Studio

1. Create a working folder, for example C:\pet.
2. Copy the precompiled ROMs from roms/ into that folder.
3. Copy your chosen normal PET EDIT ROM into the same folder and name it edit.bin.
4. Copy config/petmenu2k-onerom-hostcontrol.json into the same folder.
5. Check the file paths inside the JSON. By default they expect c:/pet/*.bin.
6. In One ROM Studio, use Create and load that ROM config JSON.

One ROM layout

config/petmenu2k-onerom-hostcontrol.json is the One ROM Studio / web app config used to build the full One ROM image with USB and host-control plugins enabled.

Expected flash layout:

Slot	Image
0	roms/petmenu2k.bin
1	normal PET EDIT ROM, not included here
2	roms/pettester.bin
3	roms/petieee2k.bin
4	roms/petromid2k.bin
5	roms/diagclipedit2k.bin

The JSON currently references c:/pet/*.bin. Put the ROM files there, or edit the paths before compiling the One ROM image.

At boot, holding a key forces the PETMENU path ignoring the boot marker. With no key held, the menu checks the One ROM non-volatile boot marker and if set will boot the slot 1 ROM, If not set it will continue to the menu. Only the Edit rom will currently set the boot marker to slot 1 Any other option will wipe the boot marker and always boot to menu. In the menu, any key (excluding RETURN) cycles the selected test, RETURN boots immediately, and the timeout boots the current selection. RETURN is recognized on normal 40-column graphics keyboards and on business/80-column keyboards. Default option is full Pettester rom and when initially compiled no boot marker will exist, Meaning this will boot pettester on a machine with no keyboard after a 30s delay.

Known limitations and future work

• If the One ROM boot marker is set to boot the normal EDIT ROM and the PET then fails badly enough that keyboard input cannot be read, the menu may not be reachable by holding a key. Recovery is still possible by re-imaging One ROM or using the One ROM jumpers to force a diagnostic slot, but there may be a nicer future rescue path.

• petmenu2k.bin currently runs the PETTESTER-derived VRAM size check before showing the menu. If PETTESTER is then launched from the menu, its initial VRAM check can report 1K on a 2K machine. This does not affect the main tests, but should be cleaned up.

Building

Install cbmasm, then either put it on PATH or set CBMASM to the executable path.

PowerShell:

.\scripts\build-petmenu2k.ps1
.\scripts\build-pettester.ps1
.\scripts\build-split-tests.ps1

Make:

make

The split-test script builds petieee2k.bin, petromid2k.bin, and diagclipedit2k.bin. The PowerShell scripts can optionally copy built ROMs into a VICE PET ROM directory if PETTESTER_VICE_PET_DIR is set.

Archive

Development byproducts, VICE launch helpers, duplicate/test binaries, older intermediate notes, and the original PETTESTE2K reference files are under archive/ so the root stays focused on the current release.

Credits and license

PETTESTER is based on PETTESTE2K by David E. Roberts, with later work by Andreas Signer and RetroRescues updates in this repository.

Licensed under GPLv3. See LICENSE.