juin 2011 Archives
Sun Jun 26 14:49:01 CEST 2011
mods in the ZX Spectrum!
Remember the days' when it takes a quarter of an hour to plug the console to tape recorder and tv,
then "Play" the K7, and loading was so slow that you get outside doing things and forget about it?
Well, it has plenty of used even nowadays!
Some links, if you find out one and want to take it over, ZX bookmarks.
Well, it has plenty of used even nowadays!
The ZX Spectrum is a great computer, though not as fast as a simple smartphone, it can achieve great
tasks to whom wants to take steps into electronics without an FPGA. Keep It Real & Simple!;)
There are pics of mine, you can see the peritel addon, which was design somehow to allow other homebrew =) (2 parts),
getting my base plate hole'd and letting pico in there i'll get my debug card!
Tired of getting a really blured screen, and my keyboard just broke, hence the time to hack this ZX !
So there i go for some fixes that are available on internet:
- getting a smoother display
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bypass the RF modulator, it is only needed for real TV (it operates the changes on signal to canal 36 VHF), done
then, see if YUV is better signal (direct cables from the ULA chip!) - remake the keyboard.
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the membrane was old, and crackled, a whole line was missing! though there a new rock solid keyboard for it! done
the !click! mechanical beep is driving me crazy..i should reverse the contact in each 40 switches for them to be silent..raaah - debug card
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make holes in the addon card and pico.(todo find little cuthole tool)
- writing and saving with tape interface
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the signal is not good, have to fix some hardware...see screenshot of a record in fromZX.jpg
Indeed this motivate me for saving/loading with full logic, no sound, see below. - want to communicate with addons via MREQ, not only IORQ!
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as the 48K spectrum has all his addressable space taken, this make this tricky!
Others make strong modifications to disable the 32K onboard memory for allowing external addons to offer ram, but i do not want to trash my only spectrum.
I located one free logic gate on IC4, and extension port A4 is free, the goal is then the extension is present, it will activate A4, going into IC4, that will disable the 32k onboard (i'm thinking of CAS/RAS..), thus allowing Velesoft's (or mine) ram module with some tricks
Some links, if you find out one and want to take it over, ZX bookmarks.