Mod #2 The STFM

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Joined: Tue Dec 19, 2017 2:16 pm

Mod #2 The STFM

Post by braincell » Tue Jan 23, 2018 8:56 pm

So i have a few ST's in the loft and i thought i would mod my STFM with a few bits.....

I cracked the bad boy open and found a 2 chip TOS 1.02 and an unknown memory upgrade....... :D
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OOOOH whats this....... a 2.5mb upgrade :D
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So 1st order of business was to junk the tos and goto a better version..... 1.4 rainbow of course......

Having a bunch of brand spanking 27c256 chips 100ns i thought .... why not !! i grabbed a romsplitter (PP) and split the 1.4 rom in Hatari and burned it too 6 chips....
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I then changed the 3 solder pads over to the correct setting (256)
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And there be a new TOS installed :)
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I also added the rather ubiquitous BLITTER .......

Exxos adapter ......
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And to test.......
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Next up was to program a GOTEK......
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And print and fit it into a case.......
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And then to get hack happy on the casing of the STFM
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Best to mark it out first.......

Then to dremel......
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Now , BE CAREFUL if using a FILE...... i managed to snap off a strip of casing whilst filing.....

But i made an invisible repair with 2 part epoxy later :D.

The "furry" abs after dremelling (is that a word????) can be removed easily with your fingers brushing it off.

Then to 2 part epoxy the printed plate into the case.....
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And solder a couple of port relocation cables .......
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Bung in the OLED and fire it up.......
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I also recapped the PSU whilst i was at it...........


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Re: Mod #2 The STFM

Post by exxos » Tue Jan 23, 2018 9:35 pm


So normal 256K ROMs work without any other mods ? I never tried it, always went for the 1MB ones and they do need mods as they larger. IIRC last time I looked the pinout of the 256K ROM's was different than the ST ones ?

RAM upgrade looks pretty sweet as well :) All my hardware guides - mods - games - STOS - All my hardware mods for sale - Please help support by making a purchase.

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Re: Mod #2 The STFM

Post by braincell » Wed Jan 24, 2018 8:06 pm

Sorry went a bit quick uploading all that...... The was a mobo pic of my oher ST in there (rev D)

The eproms are 256kbit - M27C256B-10F1 so 32 kbyte :)

cheap as chips off EbAY (Less than 5 quid 10)

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Re: Mod #2 The STFM

Post by Vyper68 » Sun Mar 31, 2019 9:14 am

Could you tell me more about the 3D printed holder for the Gotek? I don’t have access to a 3D printer so something like the holder and faceplate would be ideal for me.
Atari VCS2600jr - Uno Cart 2600, Atari Lynx, Atari 800XL, 1010 Cassette Unit, SIOPCUSB, Atari 130XE 512KB - Stereo POKEY - XC12, Atari 520STFM - TOS 1.04 - Blitter - 2MB RAM Expansion - Gotek USB Floppy ( HxC Firmware), Commodore C128 - JiffyDOS 6.1 - SD2IEC - Oceanic 118N - JiffyDOS 5.0, 1530 Cassette Unit, TAPuino, Amstrad CPC6128 - M4 - 512KB RAM - Gotek USB Floppy

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