Victor 9000 boot floppy,
ard at p850ug1.demon.co.uk
Thu Jan 11 13:48:40 CST 2007
> I've seen mention of a Hardware Technical Reference for the Victor.
> If anyone has a copy I'd be interested in hearing from you.
Not an official technical reference, but I did draw out scheamtics of my
Sirius (the UK name for the Victor 9000) system. It's a twin floppy model
with the normal keyboard and mono monitor.
Apart from the boot ROMs, the only 'custom' parts are the encoder ROM on
the disk controller board,a microcontroller in the keyboard and a
microcontroller on the disk controller PCB that seems to be mostly to so
with spindle motor speed control.
As you might expect (it's a Chuck Peddle design...) it's full of 6522
VIAs. There are 3 on the mainboard (user port, printer/GPIB port, system
control) and 3 more on the disk controller. Oh, the disk data
encoder/decoder is very simillar to that in, say,. a Commodore 8050.
The video hardware is a little odd in that there's 16 bit wide video RAM
which indexes chracter bitmaps stored in main memory. There are enough
'chracter' (as opposed to attribute) bits in the video RAM to allow a
separate bitmap pattern for each character cell on the screen, thus
allowing bitmapped grapghics. The UK 'Apricot' computer used much the
Ohter things to mention : The printer port is really a GPIB port with a
strange pinout in that it's driven by 75160 and 75161 (IIRC) chips. With
the right software and cable it could talk to GPIB peripherals.
The 'spare' 50 pin header (the one that doesn't link to the disk
contorller) on the mainboard is a user port. It's basically an
uncommitted 6522 VIA (well, one line is used as the clock for the sound
circuitry, but is is also available on this header) along with power
lines, grounds and a light pen input.
There's also an unconnected header -- 7 pins or so -- in the rear corner
of the mainboard. This is for sound _input_ -- IIRC it goes to the
encoding side of the CODEC, which then goes to the receiver section of a
6852. Again, the main prohlem would be the software to drive this.
It would take me a little time to find the diagrams, and as ever I don't
have a scanner, but if there's interest, I'll go digging and post
whatever info I can.
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