Search found 429 matches
- Thu Jan 11, 2024 8:12 am
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
The biggest problem is not so much getting the programs as making Microdrive carts which can be read by the OPD.
- Wed Jan 10, 2024 9:48 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
The issue with BASIC is that it doesn't fit in the 32K ROM slot size. The Telestore hacked things and fitted it in two 32K ROM slots. RAM expansions have to pretend to be ROMs in the ROMpack and then have code which hacks the OS into ignoring the "BAD ROMs" and telling where the extra RAM ...
- Wed Jan 10, 2024 9:38 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
The interface maps the floppies to the left and right Microdrives. As far as the system and applications are concerned it still has only the two Microdrives and nothing else.
- Wed Jan 10, 2024 7:35 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
I've no idea how to access it from BASIC at the moment as I don't have a fully working version of BASIC as that comes on Microdrive and isn't built in. As for the design being published. I'll work on a Mk.II which will fix a few things such as the connector having to be on the "wrong" side...
- Wed Jan 10, 2024 7:13 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
David Warne and Rich Mellor got the Computer One floppy interface ROM image to me today...
Wrote it to EEPROM, set things up, switched on and...
The interface only goes and works first time!
Wrote it to EEPROM, set things up, switched on and...
The interface only goes and works first time!
- Sun Jan 07, 2024 2:44 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
Mine only has three MOSFETs.
- Sat Jan 06, 2024 10:02 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
Oh, OK.I wonder why my system runs without that signal being high. Everything runs except the SRAM. Bad MOSFET maybe?
- Sat Jan 06, 2024 7:39 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
But the "shutdown" pin doesn't go anywhere other than to one transistor which controls the SRAM. I can't find it going anywhere else. You'd have thought it would have kept the machine from powering up at all until it was high, but it doesn't.
- Sat Jan 06, 2024 1:37 pm
- Forum: Compatibles Corner
- Topic: ICL OPD
- Replies: 180
- Views: 166846
Re: ICL OPD
I've been having issues with my OPD not starting up and giving the 5 bar error, which according to this document is "SRAM fault" OPD-Boot-Diagnostics.jpg This morning I traced the issue to /CE1 never going low. Chased the line way over to the left of the board to a transistor which inverte...
- Wed Jan 03, 2024 8:59 pm
- Forum: Hardware
- Topic: ICL OPD / Merlin Tonto Issues
- Replies: 1
- Views: 2597
Re: ICL OPD / Merlin Tonto Issues
Looks like 6 bars is DRAM and not SRAM fault from that document.