Search found 18 matches

by johnha
21 Apr 2015 03:49
Forum: OFF TOPIC
Topic: What other retro machines do you have?
Replies: 26
Views: 6327

Re: What other retro machines do you have?

From memory: Dragon 32 x3 (or is it x4?) Dragon 64 Atari 800 ZX81 Memotech RS128 Atari 520STF (512k) Atari 520STFM (1024k) Atari STE (2Mb) BBC Master 128 + Retroclinic Datacentre BBC B Archimedes A310 Acorn A3020 Acorn 7000+ Psion 3a (2Mb) Raspberry Pi running RISC OS (not quite retro perhaps?) John.
by johnha
21 Apr 2015 03:31
Forum: GENERAL DISCUSSIONS
Topic: When and How did you rediscover Memotech ?
Replies: 7
Views: 2124

Re: When and How did you rediscover Memotech ?

I'm a bit late to this but haven't been on the forum for a while - please forgive my tardiness. I was a child of the '80s micros (mostly Dragon 32/64s), but bought an RS128 off a mate at uni in the '90s (it was a whim - I had no idea what I was buying - only that it looked cool). PC's became ubiquit...
by johnha
21 Apr 2015 02:52
Forum: HARDWARE
Topic: ebay resue/basket case....
Replies: 7
Views: 1768

Re: ebay resue/basket case....

Dave wrote:Hi,nice photo - mmm, where have I seen that before ? :-)
Likewise, looks just like my old MTX512 - even down to the scratch on the far right of the base :)
by johnha
26 Feb 2013 01:54
Forum: GENERAL DISCUSSIONS
Topic: Hello from a new member
Replies: 29
Views: 8995

Re: Hello from a new member

Hi Andy, I'm a bit reluctant to start removing ROMs (on the basis they've been in there 30 yrs...), I note your site suggests that you can keep the ROM in situ but lose some functionality. Would I need to replace the PAL too? Dave - I have yet to open the RS128 up (I need to find enough time), the P...
by johnha
12 Feb 2013 00:19
Forum: GENERAL DISCUSSIONS
Topic: Hello from a new member
Replies: 29
Views: 8995

Re: Hello from a new member

Hi Dave, I got the impression that Pg 44 of the service manual suggested that 64K machines would have different links (and/or PALs) than the 32K ones? Unless there were two types of 64K machines, those with 64K on board and those with an add on card providing the other 32? EDIT - I plan to open up t...
by johnha
11 Feb 2013 02:46
Forum: GENERAL DISCUSSIONS
Topic: Hello from a new member
Replies: 29
Views: 8995

Re: Hello from a new member

OK, I see the links 6 & 7 you mentioned on Pg 44 of the service manual. Looking at the photos it seems hard to believe that the links have been 'retro-modified' had a memory board been removed from the machine.

I presume the reference to a 'blue PAL' in the manual relates to the blue sticker.
by johnha
11 Feb 2013 01:58
Forum: GENERAL DISCUSSIONS
Topic: Hello from a new member
Replies: 29
Views: 8995

Re: Hello from a new member

Thanks Dave, I meant to type "I'd be grateful if somebody could point out _where_ the PAL/GAL lives?" which you have answered :) It's not visible from the photo, but there is a break in the plastic under one of the RS232 port holes, suggesting it may once have had ports fitted. I've closed it up now...
by johnha
10 Feb 2013 19:51
Forum: GENERAL DISCUSSIONS
Topic: Hello from a new member
Replies: 29
Views: 8995

Re: Hello from a new member

Hi All, I've finally got round to opening up the 512, the RAM chips appear to be OKI M3732H-20RS chips but there's no sign of any previously removed boards etc. The board is revision 4000-04. Photos here: http://www.flickr.com/photos/john-halliwell/sets/72157632737248802/ I will get some more photos...
by johnha
07 Feb 2013 02:10
Forum: GENERAL DISCUSSIONS
Topic: Design your own 20MHz Z80 microsystem.. MTX PLUS !!
Replies: 10
Views: 4606

Re: Design your own 20MHz Z80 microsystem.. MTX PLUS !!

Hi All, I get the impression this project has stalled? If so how far did it get? I have been interested in developing a micro from scratch and this project might be something I'd consider looking at (although I'm thinking a 'generic' Z80 based system is more practical than a 20MHz MTX...). A few tho...
by johnha
07 Feb 2013 01:22
Forum: GENERAL DISCUSSIONS
Topic: Hello from a new member
Replies: 29
Views: 8995

Re: Hello from a new member

Thanks Crazyboss,

Yes, I'm considering an RM2, I just need the time to open a machine up and understand the PAL/GAL & ROM situation and how they affect the setup.

John.