'Non-working' M0001A

[equill]

Perhaps it is more akin to paying a ransom for its rescue than to a conquest, but I have just acquired—at least nominally, because I haven't yet received it—a fair-looking Plus, with original keyboard and pseudo-rodent, and a Rodime external SCSI drive.

The Rodime may cast some more light on an earlier thread about use of its platter mechanism in both SCSI and HD20 contexts.

The Plus will not be hard to get going, unless its ROMs were ripped untimely from its mother's ... (Macbeth) but I need not continue, or the CRT's screen has been separated from its neck. But time will tell.

My courier will pick up the Plus and deliver it to me next week.

de

 

[LCGuy]

Best of luck

 

[equill]

The Plus arrived today. I have to guess that it is a platinum Plus, by its colour (very little yellowed) and serial number. Its particulars are:

Macintosh Plus 1MB

Serial (on the case bottom rather than beside the brightness control): E9133BUM5880X, ie, 13th week of 1989

Bezel: 810-0379-A

Keyboard: M908M0110A0830, ie, contemporary with the Plus, and the correct model

Mouse: M906M010097103, ie, also contemporary, and the correct model

MLB: 820-0174-D (1986-87), 630-4122-A

Power/sweep board: 630-0108 International 240VAC

ROM: 342-0341 HI, 342-0342 LO (1986-87)

RAM: 2 x 256kB 120ns (Apple-branded, with TI chips), 2 x 1MB 70ns (Dated 1992, Mitsubishi chips). R8 had been clipped, correctly. R9 was never present.

CRT: Clinton 825-4002-A

FBT: Lifon E94167

Oscillator: Fox 15.667200MHz

Battery: an original Eveready 523, showing 0.14V

The Mac has only minor yellowing, on (presumably) the side exposed to natural light. Inside there was a thin film of dust on the top surface of the CRT and floppy drive. For the rest, it might have come out of the factory only this year. There were no gouges along the case seams, and the RFI shield was present and shiny clean, with only the prints, of whomever made the RAM upgrade, on it.

I replaced all the RAM with four identical 8-chip 1MB SIMMs containing Mitsubishi 80ns chips, and removed and reseated the ROM chips. No capacitor leakage or swelling was to be seen.

It had been sold as 'not working' perhaps because of its behaviour at startup: chime, raster, Sad Mac with 0300FF in a mixed black and grey screenful of short, thick vertical bars. It is the first time in my life that I have seen a hardware error (bad byte-write in memory test) accompany Sad Mac in a Macintosh.

The Plus came with Mac Plus Owner's Guide, SE/30 Owner's Guide, Rodime 20 Plus external HDD (in a style like that of the Apple HD20), Rodime Software User's Guide, and Setting Up Your Macintosh Plus.

Pics when I make the time to take them, and I mean make the time. There isn't any just lying about.

de

 

[equill]

Update.

Taking 0300FF at face value, I pulled the RAM, inspected the SIMM slots, blew them out again with canned air, and re-installed the RAM in reverse order, ie the former slot 1 SIMM became slot 4 sIMM, and so on.

Restart. No change in the mucky screenful of short vertical bars, but Sad Mac now reported 03FFFF. Noticing also that the mucky pattern on the screen varied with the brightness control, I wiggled the mains plug at its input socket to the Plus. The pattern changed continually as I wiggled, so here was aha! number 1. I replaced the mains cable, albeit that it had never misbehaved before, and voila! No more screen junk.

Presuming that the Plus really did not like its F-ing RAM (above), I then replaced the 80ns SIMMs with 9-chip 100ns SIMMs. Aha! number 2 followed. Restart was poifeck, with clear chime followed by raster followed by pointer followed by Quizzical Floppy. Don't ask me why, because I've never seem a Mac complain that its RAM was too fast, at least not until now. It is just possible that the SIMMs had been misdiagnosed as 1MB each when they are in fact 4MB, but that can be checked later. Anyway, the Mac was now ready for a startup disk. Happily it ingested a System 6.0.3 Macintosh System Tools diskette, read it, thought about that, and then spat the disk out, showing a Cross Floppy.

OK, you picky little beast. Try this System 5 Tools Disk #1 of 2. It booted, opened the volume, showed me its RAM as 4096kB in ATM, opened its System Folder, read a Read Me, and generally behaved itself.

It lives. Next will be to investigate the Rodime drive, and to try the Apple HD20 belonging to my 512Ke, as well as a SCSI drive that I am preparing for the 512Ke. The seller of this Plus may not miss the Plus any more, but may be pleased to hear that it 'does work'.

de

 

[porter]

You can now consider yourself a RAEME Craftsman.

Well done, that man.