This is NOT an easy task as we're talking about a double-sided circuit board here. If you don't know exactly what you're doing and have no prior experience with this sort of thing it's best left to a qualified engineer as you can easily ruin the circuit board, rendering the computer useless!!
Once the existing ROM chips have been removed, insert two new 32 pin IC sockets in their places.
The old ROMs are most likely of the shorter (28 pin) type, but the STe circuit board has room for
ROMs with 32 pins.
Observe the small notch at one end of the IC sockets and line them up with the silk-screen print
on the circuit board to avoid any confusion when installing the new chips.
You should have received two chips. Look at them closely and you'll find that one is marked
"E0" (or "LO") and
and the other "EE" (or "HI").
You should find similar identifications on the STe circuit board near the ROM sockets.
Insert the ROMs, observing the markings as well as the notch. Inserting them the wrong way will most likely damage both the ROMs and the computer!
Various types of ROMs can be used with the STe/Mega STe...
Use the table below as a guide on how to insert the 28 or 32 pin ROMs and how to
set the jumpers.
Type | Description | No. of pins/placement | Jumper settings |
27010 (1)
27C1001 (1) 571000 |
128k x 8 (1 mbit) EPROM
128k x 8 (1 mbit) EPROM 128k x 8 (1 mbit) ROM |
|
|
27C1000 (2)
571001 |
128k x 8 (1 mbit) EPROM
128k x 8 (1 mbit) ROM |
|
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531000 | 128k x 8 (128 kbit) ROM |
|
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27256 | 32k x 8 (256 kbit) EPROM |
|
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27512 | 64k x 8 (512 kbit) EPROM |
|
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STe TOS
(unknown ROM type) |
TOS 1.6/1.62 ROM
|
|
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1 = Different manufacturers supply this type of EPROM
with two of the pins exchanged.
Only EPROMs with the following pin assignment can be used with this particular jumper setting:
pin 2="A16" pin 24="OE"Check with relevant datasheets for the particular EPROM in question.
2 = Different manufacturers supply this type of EPROM with two of the pins exchanged.
pin 2="OE" pin 24="A16"Check with relevant datasheets for the particular EPROM in question.
You can either cut the existing jumpers and resolder them back in their new positions from
the top (component-side) of the circuit board (as the circuit board is double sided), or you
can flip it over and solder the jumpers from the solder-side. The latter takes a little more
effort as you have to remove more than just the top cover and the disk drive.
You can also turn the STe circuit board over and solder from that side if you like.
If you want to get an additional "high-density" option when formatting from the desktop you can solder a wire across the "E6" jumper pad as shown in the following illustration (you'll find the jumper pad field near the ROM jumpers on the STe circuit board).
(naturally, adding this option only makes sense if you have (or plan to install) a high density disk drive in your machine. STe computers were all supplied with double-density (720 Kbyte) disk drives.
PS: since TOS 2.06 was designed to support High-Density disk drives, the "step-rate" is set to 6ms by TOS which has the side-effect of creating a nasty grinding noise with standard 720 Kbyte (DD) drives. If you don't have a HD disk drive you can easily change the step-rate back to 3ms (as with older TOS versions) by using a step-rate changer program such as HD_FDC or Setseek which you put in the AUTO folder.
After installing TOS 2.06 you must delete the old "DESKTOP.INF" file (if you have one) and reboot. Then you can save the "NEWDESK.INF".
(If you save "NEWDESK.INF" while the old DESKTOP.INF is still in memory you'll end up with a corrupt "NEWDESK.INF". If you reboot after having deleted "DESKTOP.INF" you'll do fine).
Faulty DMA chip
Some of the early STe computers that rolled out of the Atari factory were equipped with
a faulty DMA (Direct Memory Access) chip.
This chip handles among other things the hard disk, and using one of these
computers with a hard disk can result in lost or damaged data.
Apparently this chip wasn't supposed to affect the use of original Atari hard disk drives, but as
most people nowadays use third party drives with an SCSI adapter of some sort (Link 96/97, TopLink,
ICD Link/Link II etc.) you should definitely check to see if yours is OK or not.