Another issue one. It had a bugged ROM. And well attached RAM pack.
Really well attached...
Search found 2174 matches
- Wed Dec 18, 2019 4:37 pm
- Forum: SALES
- Topic: Lardo buys another zeddy
- Replies: 317
- Views: 281142
- Sun Dec 15, 2019 6:58 pm
- Forum: Hardware
- Topic: Earliest known ZX81?
- Replies: 5
- Views: 1703
Re: Earliest known ZX81?
Very nice! Was it a kit build? I have had a few early ones (but not that early!) with ZX80 PSUs and cables that looked like they might be. My assumption was that if they bought a kit version they didn't get a PSU etc. and therefore used one that was easily available at the time.
- Sun Dec 15, 2019 6:17 pm
- Forum: Hardware
- Topic: vLA81 ULA and 16/32K internal RAM
- Replies: 31
- Views: 10758
Re: vLA81 ULA and 16/32K internal RAM
- Sun Dec 15, 2019 5:29 pm
- Forum: Hardware
- Topic: vLA81 ULA and 16/32K internal RAM
- Replies: 31
- Views: 10758
Re: vLA81 ULA and 16/32K internal RAM
Excellent post. They are there to be used and abused imo. not polished or put in glass cabinets. The first thing I did to my 80 was fit a switching reg, then ripped the guts out of the modulator to fit a composite board then finally a new ROM for ZXpand use and ended up with a much better tooter. M...
- Sun Dec 15, 2019 12:47 pm
- Forum: Hardware
- Topic: I got a ZX80!
- Replies: 10
- Views: 3354
Re: I got a ZX80!
Thanks, I'll see if I can get one the same type from Mutant Caterpillar that will involve no soldering to the board. As an aside, the other week I got a very, very early ZX81 (8106 Modulator, 8102 ULA, 8028 RAM) which actually had a ZX80 PSU with it, the same ZX80 type cassette and RF cables and sl...
- Sun Dec 15, 2019 12:43 pm
- Forum: Hardware
- Topic: vLA81 ULA and 16/32K internal RAM
- Replies: 31
- Views: 10758
Re: vLA81 ULA and 16/32K internal RAM
Presumably the major issue with bent pins on an IC is that it makes maintenance more difficult in the future? Would it be possible to fit a low profile socket, then fit another socket (pins bent out) and put the IC in that? Only the sandwich socket is modified and the RAM chips are easily swappable?...
- Sat Dec 14, 2019 9:08 pm
- Forum: Hardware
- Topic: vLA81 ULA and 16/32K internal RAM
- Replies: 31
- Views: 10758
Re: vLA81 ULA and 16/32K internal RAM
Thanks Chris. Just one or two questions.... :D :D * I assume L1 needs to be changed to L2? * With the mod as shown the zeddy has 32K of RAM? * Does that leave it in a state where most / all commercial software will still work? (Concerned that games that expect things to be in a specific RAM location...
- Sat Dec 14, 2019 8:53 pm
- Forum: Hardware
- Topic: I got a ZX80!
- Replies: 10
- Views: 3354
Re: I got a ZX80!
I have a programmer. But to fit a newer one on a standard eprom would need an adapter on the board and that wouldn't fit at all (and I don't want to make any changes at all to the actual board, even soldering). I thought a ROM-el would fit, but it's a gnat's whisker too tall. I remember seeing an o...
- Sat Dec 14, 2019 7:31 pm
- Forum: Hardware
- Topic: I got a ZX80!
- Replies: 10
- Views: 3354
Re: I got a ZX80!
Got this today. And it was a bargain if I do say so! I discovered that it has a vigin exp port too, never scratched by a RAM pack, much to my delight. It has a few marks and a little rip in a lower corner. It came with a ZX81 ROM and ZX81 keyboard overlay. I removed the overlay and as there's not m...
- Sat Dec 14, 2019 7:30 pm
- Forum: Hardware
- Topic: vLA81 ULA and 16/32K internal RAM
- Replies: 31
- Views: 10758
Re: vLA81 ULA and 16/32K internal RAM
I've done a few of these (and have done a lot of fiddling with various configurations and written a lot of emails bothering Mr Ingley with silly questions) and there is no need to cut any tracks, just bend out 4 pins (1,2,23,26) of the 32k RAM chip and connect to address lines A11 to A14. Note that...