Huxley Posted July 5, 2008 Share Posted July 5, 2008 Hi guys, So, last year I took in a massive haul of surplus computer equipment from the Los Alamos Labs here in New Mexico. One of the cool items that came in that batch was an Atari STF, which has been sitting in my garage all this time. So, just yesterday I finally got the itch to check this thing out, and I quickly noticed that this system seems to have had at least one modification - what appears to have been a user-installed 2-position toggle switch on the right hand side, which is wired with some very thin wires to the left side of the CPU daughtercard. Also, it's clear that whoever installed this switch mod started by drilling a hole in the case... and then decided to position the switch a bit lower and drilled a second hole. I'll attach some pics below. I'm a retrocomputing hobbiest (and have been for years), but I have almost zero experience with Atari systems. Is this type of mod a common thing on these systems? What would it be used for? I've seen one reference to a drive-switch on some ST systems, but wouldn't that be wired to the drive itself, rather than the CPU board? Anyway, I I won't know for sure until I fire this thing up. I'm in need of pretty much every accessory to make this thing work - a video cable, a mouse and some software. I guess I'll start poking around on the trading forums and eBay, unless anyone who reads this has any spares they could part with (for cash or trade!). Thanks! Huxley Quote Link to comment Share on other sites More sharing options...
nathanallan Posted July 5, 2008 Share Posted July 5, 2008 That board that is in the third picture is definitely not stock. I'll hazard a guess that card is some kind of upgrade card, and that switch enables/disables it. I found a page about that board's processor. Other than this, I am not going to hazard a guess. Okay, maybe one, maybe a better way of running the computer? Or a proprietary OS, other than what we all are familiar with?? let us know what happens when you boot her up!! I will bet it's not running TOS of any kind. At least when the switch is on. Um, little advice, power down the machine before you hit the switch, cause you never know what may/may not be fry-able. if it was me, I would boot into either "mode" of the switch. Sweet find!! Los Alamos, even!! I wish something like that would turn up here in El Paso! Nathan Quote Link to comment Share on other sites More sharing options...
+remowilliams Posted July 5, 2008 Share Posted July 5, 2008 Daughterboard looks like a 16Mhz accelerator, though I'm not familiar with what type. If what is pictured is all that you have, you will need a power supply, keyboard, and floppy drive to get 'er going. Quote Link to comment Share on other sites More sharing options...
Huxley Posted July 5, 2008 Author Share Posted July 5, 2008 That's awesome - thanks for the info! I did notice the beefed-up 68000 chip on the card, but again, being unfamiliar with the ST line, I wasn't sure if it was standard or not. You mention your suspicion that it's not running TOS when the card is active - what would be the alternative? I've got other machines (like a Commodore 128 and DEC Rainbow) that could switch operating systems, but again, I don't know enough about the Atari line to know what other options there were. Was the normal TOS not friendly with accelerated processors? Anyway, thanks again for the info - this should get interesting! Huxley Quote Link to comment Share on other sites More sharing options...
Huxley Posted July 5, 2008 Author Share Posted July 5, 2008 I should've posted a "before" picture - those pics were post-teardown. I do have the floppy, power supply, keyboard, etc., they'd just been removed prior to taking those pics. Huxley Quote Link to comment Share on other sites More sharing options...
+poobah Posted July 5, 2008 Share Posted July 5, 2008 There were a variety of 16 MHz accelerators for the STs This is most certainly one of them, should run normal TOS. I see no eeproms on the board, just a bunch of glue and cache ram nice find. Quote Link to comment Share on other sites More sharing options...
nathanallan Posted July 5, 2008 Share Posted July 5, 2008 I didn't mean it may be unfriendly or incompatible, I meant considering where it came from it might have its very own custom-made operating system courtesy of Uncle Sam! Then again they may have just used chips on that daughterboard and not used the ones on the motherboard. Who knows. When you get the chance to fire her up, you'll see what comes up on the screen. I wouldn't be surprised if it's some weird port of Unix, again, considering the source. This could be considered a part of Electronic Anthropology!! Nathan Quote Link to comment Share on other sites More sharing options...
krupkaj Posted July 5, 2008 Share Posted July 5, 2008 It is accelerator HBS 28, running 68000 at 28MHz. It has also fast cache for the CPU. It is very fine accelerator. Quote Link to comment Share on other sites More sharing options...
Huxley Posted July 6, 2008 Author Share Posted July 6, 2008 It is accelerator HBS 28, running 68000 at 28MHz. It has also fast cache for the CPU. It is very fine accelerator. Awesome! Thanks for sharing that info! I just did a (quick and dirty) Google search for the info you shared, but didn't find anything. Do you know of any additional information about this upgrade? Drawing on my experience with upgrading the CPU's of older Macs, they often need special software drivers to work properly - do you think that this would be the case here? Thanks again! Huxley Quote Link to comment Share on other sites More sharing options...
krupkaj Posted July 6, 2008 Share Posted July 6, 2008 (edited) I am not sure at the moment. It is possible to control it by switches connected to the pads on the ledge (I think the switch in the picture is already connected there) Just try to run some benchmark or sysinfo and you can see the speed of the CPU. I have to ask my friend who own this accelerator if there is some software necessary to run. I know it is possible to upgrade HBS with FPU 68881 - you need small board with socket which fit to the two connectors on the top of the HBS. BTW I see you have 36MHz version, you are lucky Edited July 6, 2008 by krupkaj Quote Link to comment Share on other sites More sharing options...
nathanallan Posted July 6, 2008 Share Posted July 6, 2008 Well, that was my stab at the picture. Glad I was wrong, good that it taught me something. Never seen an upgrade like that one! Nathan Quote Link to comment Share on other sites More sharing options...
krupkaj Posted July 6, 2008 Share Posted July 6, 2008 (edited) I think it comes from Germany, so it is rare in US BTW here are photos of my friend's MEGA ST - the sandwich with 3 boards: MAGNUM card with 16 MB of TT RAM, accelerator HBS 28 with FPU board on the top and this is not all, now there is also NOVA graphics card in MEGA bus slot, but unfortunately I haven't pic of that. It is great machine to run MiNT on Edited July 6, 2008 by krupkaj Quote Link to comment Share on other sites More sharing options...
oky2000 Posted February 25, 2009 Share Posted February 25, 2009 Why is it using a 16mhz rated 68000 to run at 28mhz? In fact was there actually a standard 68000 @ 28mhz rating from Motorola in that chip package? Most 68000 Accelerators were actually 16mhz anyway makes it a lot simpler to just double up the CPU or multiples of the original 8mhz cpu bus. I always wanted one when I got my STM just so Gauntlet 1 would scroll horizontally a bit better without bogging down and STeeM proved 2 decades later that it would have been disastrous for my school studies had I done that as it is a fine fine game @ 16mhz Quote Link to comment Share on other sites More sharing options...
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