exxos's Atari, Amiga & retro forum

The mod daughter board design is now complete. The Shugart cable adapter board may interfere, or may not we'll see.

I've a CD2014BE in stock so I'm using that for the flip-flop clock divider and a 74LS04 to invert the /DSKCHG signal to be /READY. Jumpers to revert to the standard set-up of course.

I was amazed that the WD2797 was actually in KiCad already!

Anyway, time to send this one off to PCBway...

(The centre "chip" will actually be the the pins which go down into the original socket.)

Sounds like good progress, looking forward to the next installment 😁

I thought I'd see if I could get CheckIt to run on the Apricot and see what it thought of the machine.

Running CheckIt 1.010 initially it gave a couple of messages and then hung the machine, so I then run the IBM PC compatibility program found on the GEM floppy image before running CheckIt and it worked, at least to the point of the front page.

Anyway, it sort of worked. The system information page seemed to think that the machine has 2.7MB of RAM! (Also it printed a whole load of rubbish for the BIOS version.) Many other functions caused the machine to crash though.

However, running the performance test was a bit interesting...


It seems that the machine has a 547MHz 8088 in it! :lol:

stephen_usher wrote: 27 Jun 2021 09:50 It seems that the machine has a 547MHz 8088 in it! :lol:

Are you sure @terriblefire hasn't been mucking about inside? :lol:

derkom wrote: 27 Jun 2021 12:10

stephen_usher wrote: 27 Jun 2021 09:50 It seems that the machine has a 547MHz 8088 in it! :lol:

Are you sure @terriblefire hasn't been mucking about inside? :lol:

Hehehe :lol: :crazy:

Well, that's interesting. The PCBs for the floppy cable adapter arrived in Leipzig in Germany yesterday and this evening they're back in Shenzhen in China!

On another front, it looks like the serial port on the F1 had died this evening. I attached a serial mouse and initially I could see data using my RS232 monitor device. Lots of green lights with some flickering to red as it's supposed to. About 5 minutes later I see all red LEDs lit and nothing on the mouse side of things. Unplug the mouse and red on the TX line (which should never be). Looks like something to investigate when I get the time.

This thread is shaping up to be as long as one of mine :)

:dizzy:

rubber_jonnie wrote: 29 Jun 2021 09:25 This thread is shaping up to be as long as one of mine :)

:dizzy:

Hehe. Yeah, well, maybe the floppy cable connector and WD2797 daughter board will arrive together at this point, after the cable connector has finished its World tour, or they'll forever be bouncing between Europe and Chna until the end of time. :-)

As for the F1, the serial port was working again this morning for a while and then stopped.

It can only be the RS232 line driver chips, though I'm not sure which one as I got the interface to work again by freezing them both. I should have done one at a time.

Though the +12V rail is rather high at 13.5V!

P.S. It's the output driver chip '1A' I think. It's an MC1488.

OK. It's not the power draw from the mouse which is causing the failure as it does it on its own.

Time to search for an MC1488!

Oh, good. They're readily available, or at least the TI equivalents are. I got some MC1489 chips as well while I was at it.