nice glitching story
Diehard Z80 coders will enjoy about the extraction of 's Boot ROM which was finally achieved last week after 10 years.
He did it by powering & clocking the processor from an FPGA, cycle counting up to the right point, suspending clock and powering down for several seconds, resuming and injecting NOPs for a while until vectoring to a ROM readout routine.
That followed the recent cracking of original Gameboy ROM by decapping, and scanning under a microscope.
The draft IDA disassembly is .
| Look Here -> |
that's dedication......
The addiction i think
When you do things right, people won't be sure that you have done anything at all
crazy but brilliant
Nice work.
Looks like 8 green wires and 8 blue wires .
I could do the hardware part soldering and all but hats off to the other guy.
A great effort
Nice Work
Looks like fun
Nothing beats a challenge with a thrill and learning on the way...
When I went to the local tip recently, I did what most males do and checked for any valuables that some wastrel had thrown away.
I found a Dick Smith DZ200 computer and tape recorder plus all the manuals.
I didn't have the heart to leave it there to be crushed by the council bulldozer so I dusted it off and brought it home.
Buggered if I know what I'm going to do with a 1983 vintage Z80 powered clunker, but you just never know.
They were very popular in mid-80s because of their low cost. A friend of mine had one of those began crashing after a year because of poor quality PCB and ultra-cheap construction.
To fix we rolled up our sleeves, stripped it down and rebuilt it completely, modding heavily. Remounting in a new case we gave it a stack of extra 6116 RAMs, hardwired a 16K DRAM expansion unit and gave it a new beefy power supply.
The VZ-200's chiclet keyboard was abominable so we replaced it by an external plug-in keyboard made from a Super-80/Microbee keyboard assembly.
Its inbuilt BASIC was reasonable (licensed from Microsoft) but it offered no easy way to do Z80 coding so we ported the monitor over to it and got it working, which was fun. I've still got its disassembly here somewhere. Ahh, the nostalgia!
It got thrown out years ago and I wish we took photos of it 'cos it looked a lot like from Blakes' 7.
The first computer I had anything to do with was The Sinclair that I borrowed from a friend, I then bought a DZ200.
Microbee?, the stuff of dreams in the mid 1980s, I couldn't afford one but I used to steal programs written for them and mod them to run on the DZ.
I remember at that time there was someone in your neck of the woods who was writing some very clever software for the Bee.
I bought and built the Dick Smith Super 80 Kit .
Had to buy a Frequency counter kit to get it going LOL. Still got it
It was tape storage.
Then built a 80 column display board and a vero board floppy controller.
Thos were the days 8 inch disk and rewriting the code when ever were got a different drive.
PS also we had monthly computer meets at Croydon ?? it was at a church hall we would take our hacked up machines to show .
Last edited by pieces; 04-10-09 at 08:39 AM.
You're probably thinking of VK7TM, a very clever man, sadly missed. R.I.P.Originally Posted by BlackDuck
OK Guys, since we're on the topic of dinosaurs, my Exidy Sorcerer Mark II is still in the garage. I bought it in 1981 with Micropolis 120k single sided hard sectored 5.25in twin drives, an S100 expansion bus and an Epson MX-80. The printer still works, the S100 probably does although I can't say if the expansion cards work (three 8k memory cards) because the computer won't complete its normal boot cycle to the command prompt. Anyone remember having to type GO C100 in order to boot CPM or Micropolis DOS? Although I had Micropolis Basic, Pascal MT+ and COBOL in addition to the ROM pac, all running in 56k of ram (32k on board + 24k from the S100), programming in Z80 Hex was far more fun. Them were the days!
Anyway, I can't bring myself to tossing it out. Years back I changed the zilog Z80 with a new sharp Z80, but that didn't help because the problem almost certainly lies in the rom chip. One day I'm going to fix it and if I can't I'll burn an Exidy emulator onto a chip and rebuild the computer around it. As they say, you never forget your first love.
UFO
Edit: If anyone born after 1981 wants to check out the capabilities of this computer, Java demos are available here:
Last edited by ufosarereal; 04-10-09 at 05:04 AM.
Tom Moffat, Yes a very clever man indeed, I had some frustrating times and learned a lot modifying some of his MicroBee programs to run on DZ200s.
Exidy Sorcerer, great number cruncher in its day.
Speaking of dinosaurs, does anyone remember Electronic Australia's EDUC8.
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