From 3bc2cb07dadfddc56cb3dcea6962776f8a3a902d Mon Sep 17 00:00:00 2001 From: Andreas Baumann Date: Wed, 17 May 2023 21:10:58 +0200 Subject: updated IMC-2001 status --- content/hardware/imc-2001.md | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) (limited to 'content') diff --git a/content/hardware/imc-2001.md b/content/hardware/imc-2001.md index 3524717..1ea1ec5 100644 --- a/content/hardware/imc-2001.md +++ b/content/hardware/imc-2001.md @@ -13,15 +13,6 @@ Trying to fix several issues: - the CRT shows some flickering and diagonal effects. Testing on an old TV shows the same issue (so I suspect it's some grounding/shielding issue with the new PSU). -- floppies written read/written with Fluxengine don't really work either - on the real hardware or the emulator. Suspecting a encoding/decoding issue. -- the floppy drives read floppies (both) but they don't write to floppies - (when copying in CP/M or creating a file), they work when formatting - a drive on CP/M though. ~~Could be a side-effect of the PSU not working properly.~~ - The PSU has been replaced, the voltages look ok, so I rule out the PSU. - Could be some missing code in the Apple ROM (but that would be weird to - call 6502 firmware code from the Z80 CPU). It could also be the write - current being to low for writting (but why does formatting a drive work then?!) - the lever moving the contacts between 40-character and 80-character mode for the CRT output is corroded, doesn't always make contact and produces a flickering image @@ -32,10 +23,27 @@ Trying to fix several issues: - keyboard cable is broken, at least the data line - the paddle and the joystick connectors miss some legs for putting them into the sockets on the motherboard +- the second floppy drive (the more used one) now sees floppies always as + "write protected". Diagnostic tests show alignment issues of the drive, this + could be true, or the clone always had a different alignment than a default + Apple 2 drive? - possibly much more Fixed issues: +- ~~the floppy drives read floppies (both) but they don't write to floppies + (when copying in CP/M or creating a file), they work when formatting + a drive on CP/M though. ~~Could be a side-effect of the PSU not working properly.~~ + The PSU has been replaced, the voltages look ok, so I rule out the PSU. + Could be some missing code in the Apple ROM (but that would be weird to + call 6502 firmware code from the Z80 CPU). It could also be the write + current being to low for writting (but why does formatting a drive work then?!)~~ + So, yes. DOS 3.3 and CP/M both use some ROM routines from ROM1 to write to disk. + Works now. +- ~~floppies written read/written with Fluxengine don't really work either + on the real hardware or the emulator. Suspecting a encoding/decoding issue.~~ + Updating Fluxengine solved the issue, also choosing 96dpi 5 1/4" for the real + floppy drive. :-) - ~~the keyboard reset line cannot be taken to ground on the keyboard, works with shrtening ground and reset though just fine. Must be a bug on the ICs of the keyboard controller or a broken trace.~~ Fixed with a botch @@ -83,6 +91,8 @@ Known things to work: - the 80-columns card (a Videx Videoterm or rather a clone of it) works just fine. - the highres graphic mode works just fine, I can run "Peter Anvin Chess" and play it. - Applesoft BASIC works fine +- the new Super Serial Card II I got works fine, though it looses characters + (without parity and adding some delay in minicom). Definitely usable. # Images -- cgit v1.2.3-54-g00ecf