10.6 SST

Gadgets by Small SST

Das "SST" Beschleunigerboard stammt aus dem Hause "Gadgets by Small", welches auch durch den Macintosh Emulator "Spectre" bekannt wurde. Da beide Erweiterungen vom selben Entwickler kamen, war es kein Wunder, das der SST problemlos mit dem Spectre Emulator zusammenarbeitete.

Auf dem SST Board wurde ein MC68030 als CPU sowie eine MC68882 als FPU eingesetzt. Beide liefen mit 33 MHz, wobei die FPU auch separat von der CPU (höher) getaktet werden konnte. Zusätzlich befanden sich 4 Steckplätze für 30-polige SIMM Module (max. 8 MB TT-RAM) auf der Platine. Ein TOS 2.06 wurde als Betriebssystem auf dem SST Board verwendet.

Der Beschleuniger verfügte über keinen Zwischenspeicher (Cache) und war deshalb etwas langsamer als vergleichbare 68030 Beschleunigerkarten. Der Preis für Karte war schon fast an der Schmerzgrenze. Dieser betrug Anfang 1992 ca. 2800,- DM inkl. 8 MB RAM.

Here is some old infos (sorry only in english) that helped me and some others get the T-36 working on our Megas and ST's. It might help PAK owners if they have problems too. (!nl

NOTE:

The following is taken from the installation instructions for the Gadgets by Small SST manual. It is intended for the MegaST, but with a little luck, you will find the procedure the same for a 1040ST. The 7407 (U2) mentioned in the documentation is ( I think) located in a different area on the 1040 than it is on the Mega ST. The trace on the DMA that must be cut may also look different than described here, but should be the same pin number. I changed the floppy controller chip as my machine was having problems to begin with. The Yamaha sound chip is located on the DMA bus, and if not running to specification, will inhibit normal DMA operations. If after you perform this mod you still have problems I suggest that it also be changed. I found that the T36 card was unreliable when the FROM jumper was set and once removed I have had no further problems.

The following is Copyright by Gadgets by Small ,Inc. and George Richardson.

If your video turns on but is all scrambled up, and you have a blitter on, it's an easy fix. Remember that floppy disk you make before you took apart your ST? The one that has the blitter turned off in the desktop information file? Use that floppy to start up with the blitter off. Some blitter's just can't handle the SST unless they are turned off. With a blitter on, results vary considerably, depending on what program you are running. We recommend not worrying about it, and just leave the blitter off.

If you have a "black screen" the first thing to try is power off and unplugging the hard disk cable (the DMA cable) from the back of your ST, and then try turning on your ST. (Some hard disks conflict with the RESET line, so the 68030 never gets it's"wake up call", or worse, gets it at the wrong time). If you get no video in 3-5 seconds, shut off the ST. It's not the hard disk RESET problem. If you get normal video with your hard disks unplugged, you will need to do the RESET line fix.

There's two ways to do this fix, the quick and dirty (and not always reliable) way, and the right way, which involves cutting traces on your ST motherboard. For the quick and dirty way, just solder a 1K resistor between pin 2 of the 7407 and pin 14 of the 7407. The 7407 is labeled U2 on the ST motherboard, and is located under the power supply. This will not solve everyone's hard disk problem; for that you have to do George Richardson's complete Hard Disk RESET Line Fix, detailed in a latter chapter.

                pin 14         7407
                        *
                        *******
                        *******
                pin 2     *

Georges's Hard Disk Fix

Sometimes an SST won't boot with a hard disk attached, won't boot with a particular hard disk attached, or won't boot with more than one hard disk attached. This is because when running at higher speeds, the SST is particularly noise sensitive. Most of the lines coming into the SST are buffered and cause no problem, but the RESET line is bidirectional, so it can't be buffered on the SST.

This problem, if it happens, only shows up with hard disks attached because the RESET line runs out to the DMA port. The hard disk you have may not be buffered; if they aren't, the RESET line can pick up a lot of noise, which will confuse the 68030. This problem can also show up as DMA failures on a regular unaccelerated ST.

IMPORTANT:
Read the entire procedure before beginning. If any part of it doesn't make sense, don't perform the modification! Find someone who is experienced with electronics to do it for you. Use this information at your own risk. Gadgets by Small, Inc. assumes NO responsibility for any damage or expenses arising from the use of this information. If you are determined to fix this ST problem yourself, you'll need some "wire wrap" wire, wire cutters, solder, a drill with a tiny drill bit installed or an X-acto knife, and a 1k ohm 1/4 watt resistor.

1. Take apart your Mega, and remove the floppy drive, power supply, and SST if it is installed.

2. Find the 7407 chip labeled "U2" on the Atari ST motherboard. It is located under where the power supply was.

3. Solder a shore piece of wire from pin 2 of U2 to pin 13 of U2.

4. Then solder a 1k resistor to U2 between pin 14 and pin 12.

                pin 14 *
                        *******
                pin 2   *******
                          *

5. Now you need to solder a wire from pin 12 of U2 (there is already a resistor soldered to that pin) to pin 12 of the DMA Connector on the back left corner of the ST motherboard. The easiest way to get the wire to pin 12 of the DMA connector is to solder it to the underside of the ST motherboard.

                pin 12 -------*
                * * * * * * * * * 11
             10 * * * * * * * * * * 1

(pin 12 under the DMA connector, underside of motherboard).

6. On the top of the ST motherboard next to the DMA Connector is a trace which looks kind of like an upside down "T". The easiest was is to use a tiny drill; but be very careful, and do not drill very; deep! you can also use an X-acto knife to cut the trace. Make sure that you cut the trace all the way through, and don't accidently cut any other traces.

DMA Connector
     I ___cut here
O---I--------------------