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+title = "IMC-2001 Status and Todo List"
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+
+# Todos
+
+Trying to fix several issues:
+
+- CPM65 works on the machine in 40-character mode (hacked), the
+  Videx card is the next goal. The 40-character mode still is quite
+  unreliable and crashes the machine, the screen TTY driver is still
+  to be done for apple2.
+- the 5V rail is on 4.5V now, causing issues with the keyboard (the
+  length of the cable) and with the paddles. Not clear, whether this
+  is the PSU (which is also showing 4.7V without load) or something
+  on the motherboard. There are two +5V lines on the original PSU and
+  only one on the replacement PSU, maybe that's a problem?
+- the keyboard beeps and issues '=' and '/' characters when connected
+  to a longer serial cable, no problems when connecting the botched
+  wire from the old connector on the keyboard PCB directly to the
+  computer. Some shielding or capacitance issue? It also appeared
+  only after playing with the paddle connectors.
+- the new paddle connector with DIN-5 connectors works somewhat with
+  paddle 0, though the nob is not totally up when on 255. This indicates
+  again a capacitance issue, probably with the cable itself?
+- two new teac drives turned out to have the very wrong connector for
+  an Apple \]\[ disk controller, some adapted has to be designed and
+  a PCB has to be printed.
+- strange issues with floppy images not working in LinApple or also
+  not on the real computer, always bailing out in the monitor in strange
+  locations. Used Fluxengine and ADTPro to get images, they are identical.
+  Checked the RAM of the machine, no errors. Must investigate if boot
+  addresses are the issue (48k floppy masters not working on 64 or similar
+  issues)
+- HGR shows a line on row 0 only partially. This could be an adjustment issue
+  of the CRT image or also bad RAM.
+- 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).
+- the CRT is producing some flickering when turning the brightness nob,
+  this should be fixable with some deoxit.
+- 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?
+- the paddle wire is self-made on paddle 1 and quit a mess. Doing a rewire
+  with DIN-5 connectors which then lead to a 9-pin DSUB-Apple ][ standard
+  joystick connector, which will go to the 16-pin DIP socket on the motherboard.
+  The original joystick connector has a completely weird layout and is not usable
+  (it has no Apple 2 layout)
+- really bad design to connect DIP 2x8 cables of the joystick and the paddles
+  directly on the motherboard, you pull the cable a little bit too much and
+  you tar out half of the motherboard.
+- possibly much more
+
+# Fixed Issues
+
+- ~~the paddle and the joystick connectors miss some legs for putting them into
+  the sockets on the motherboard~~. No essential pins are missing, will
+  rework this anyway as a 8x2 DIP to 9-DSUB, from there to an adapter
+  where you can connect 2 DIN-5 cables, needs rewiring of both paddles.
+- ~~paddle 0 seems to be a little bit shacky (the button works unreliably)~~.
+  DeOxit in the button helped. Works much better now.
+- ~~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~~. The box is heavily sealed and there
+  is no easy way to fix it. Using an audio switch box for switching modes now
+  (the cables are standard audio-like cinch connectors).
+- ~~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
+  to bridge the broken ribbon cable between keyboard matrix and the PCB with
+  the controller logic.
+- ~~ROM 1 with BASIC is broken (and gets really hot). This explains
+  the booting issues.. (will be tricky to get a replacement). The
+  board layout doesn't fit to the original ROM sizes too..~~
+  Got an AT28C256, no more frying of chips, Apple Basic prompt appears,
+  tested some commands and it seems fine. The 32k ROM has to be filled in
+  starting from 0x6000 with #E000-$EFFF and from $7000 with $D000-$DFFF.
+  If this ROM is ok we will see.
+- Reseated and deoxied all ICs, some of them were quite corroded, at
+  least 3 more turned out to be bad. ~~Sadly it didn't have an effect on
+  ROM 1 not getting hot (must be something else).~~ The new replacement
+  ROM works fine and doesn't get hot. So I actually blame it on the ROM
+  itself causing the other ICs to fry and not vice-versa.
+- ~~power switch made some hissing noises, it was not the switch, now
+  the original power is dead (and some transformers are humming). Ordered
+  a Apple 2 replacement PSU, waiting for it..~~
+  The new replacement power supply works like a charm, also replaced
+  the power switch, the old one was too unreliable.
+- ~~sometimes I get into the monitor~~
+- ~~lower-nibble bit 3 of the key
+  being pressed is missing, unclear where it is lost, I suspect a
+  bad register on the motherboard holding the current ASCII value of
+  the key pressed or something similar~~. Replaced a bad 74LS257N,
+  works now just fine.
+
+# Not fixed issues:
+
+- ~~The 220V fan no longer works.~~
+  I just disconected it, I don't think, it really helps to cool the system.
+
+# Known things to work:
+
+- The keyboard works electronically (8039 MCS-48 like CPU with a 2K EPROM),
+  has a new serial cable now and is fully functional
+- the Rockwell R6502 CPU has a phase 0 clock and seems to go through
+  address lines and output data (another strong indicator is the 'Apple \]\['
+  sign on the monitor when switching on which indicates 6502, 40-character
+  ROM, video circuit seems to be just fine).
+- Monitor is working just fine (which is sort of amazing for such an old
+  CRT monitor).
+- I can boot from a Apple \]\[ CP/M 56k floppy and I get a prompt, now
+  as the keyboard works and the CP/M on the 80-character card I can also
+  assume the Z80 is working just fine.
+- 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.