Mod #2 The STFM

Blogs & guides and tales of woo by forum members.
Post Reply
braincell
Posts: 4
Joined: Tue Dec 19, 2017 2:16 pm

Mod #2 The STFM

Post by braincell »

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
20171218_113754.jpg
20171218_113754.jpg (217.55 KiB) Viewed 4413 times
20171218_115342.jpg
20171218_115342.jpg (178.83 KiB) Viewed 4413 times
OOOOH whats this....... a 2.5mb upgrade :D
20171218_115346.jpg
20171218_115346.jpg (227.44 KiB) Viewed 4413 times
20171218_115350.jpg
20171218_115350.jpg (290.16 KiB) Viewed 4413 times
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....
20180114_125315.jpg
20180114_125315.jpg (196.36 KiB) Viewed 4413 times
I then changed the 3 solder pads over to the correct setting (256)
20180113_152504.jpg
20180113_152504.jpg (119.17 KiB) Viewed 4413 times
20180113_152422.jpg
20180113_152422.jpg (271.21 KiB) Viewed 4413 times
And there be a new TOS installed :)
20180114_125251.jpg
20180114_125251.jpg (100.61 KiB) Viewed 4413 times
I also added the rather ubiquitous BLITTER .......

Exxos adapter ......
20171218_120755.jpg
20171218_120755.jpg (189.96 KiB) Viewed 4413 times
20171218_122521.jpg
20171218_122521.jpg (167.37 KiB) Viewed 4413 times
20180113_152427.jpg
20180113_152427.jpg (207.83 KiB) Viewed 4413 times
And to test.......
20171218_132724.jpg
20171218_132724.jpg (100.29 KiB) Viewed 4413 times
Next up was to program a GOTEK......
20180114_145624.jpg
20180114_145624.jpg (179.06 KiB) Viewed 4413 times
And print and fit it into a case.......
20180120_151825.jpg
20180120_151825.jpg (140.47 KiB) Viewed 4413 times
And then to get hack happy on the casing of the STFM
20180113_154125.jpg
20180113_154125.jpg (172.38 KiB) Viewed 4413 times
Best to mark it out first.......

Then to dremel......
20180113_154712.jpg
20180113_154712.jpg (101.36 KiB) Viewed 4413 times
20180113_154727.jpg
20180113_154727.jpg (95.88 KiB) Viewed 4413 times
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.....
20180113_175058.jpg
20180113_175058.jpg (120.92 KiB) Viewed 4413 times
And solder a couple of port relocation cables .......
20180113_172141.jpg
20180113_172141.jpg (135.16 KiB) Viewed 4413 times
Bung in the OLED and fire it up.......
20180121_121554.jpg
20180121_121554.jpg (95.25 KiB) Viewed 4413 times
I also recapped the PSU whilst i was at it...........

Lee
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Mod #2 The STFM

Post by exxos »

:bravo:

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 :)
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
braincell
Posts: 4
Joined: Tue Dec 19, 2017 2:16 pm

Re: Mod #2 The STFM

Post by braincell »

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)
Vyper68
Posts: 4
Joined: Fri Mar 29, 2019 9:56 pm

Re: Mod #2 The STFM

Post by Vyper68 »

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
Post Reply

Return to “MEMBER BLOGS”