ToToTEK.COM

[Mystic_Merlin]

Hello rodneyk,

Thanks a lot for your input. That would take some time indeed to unsolder and wash everything, even though that's probably the best thing to do. I didn't know about the vinegar trick but I heard of the "bath" solution with arcade board owners.

Still, some traces were corroded to the point there was no continuity, too bad I found them after unsoldering the PAL.

I must agree I probably had not the right approach. Moreover that I got a bit impatient on the fragile PAL and there's not much left of it...

I documented the mod the best I could considering what I had. As kyuusuaku stated the hardware mod alone would not allow the SP3200 to load HiRom unless there'd be some BIOS modification (which apparently didn't occur) or ROM loader, it's hard to tell if we would have ever found how/if this mod ever worked.

The cut off pin was also suspicious.
I can only report my results as they are of today:

Before any operation was done to the copier
- I can send via Ucon but getting garbage or black screen
- cart size is reported as 0M, some cart put on the top bring up the Supercom menu, some other a black screen

After taking off the PAL, restoring original connections and bridging some cut traces
- cart size is reported correctly, all carts bring the Supercom menu with proper cart size
- I can not send via Ucon

Also I made a DB25<-->FD34 connector providing +5v to the drive from a PSU or directly from another copier and all I was getting from the drive was the motor spinning a bit but no light. I don't believe it's a power or data cable issue, I doubled check everything.

The ALTERA chip and its socket look fine. Could there be any other mod than the BIOS? The Winbond chip?

Sorry I couldn't shade more light on this HiRom mod, all I can hope for is finding another SP3200 to make some comparison.

kyuusaku, the SRAM mod would sure be interesting on a working copier...till I get another one...

[kyuusaku]

There's nothing else to be modified, it's gotta be a software thing... Since CrackLtd did these mods, wish he could say the order of operation... From memory the Magicom "HiROM fix" in Schweino's archive included an enhanced BIOS to load early Pro Fighter HiROM dumps. I don't have the file handy though to check it out. Perhaps it can run from DRAM.

Here's the core logic to the switch:

[CrackLtd]

Well, all i can say is, after i did the HiROM fix(*) to those old Magicoms the HiRom Games instantly ran without any manual switching or anything. However the transferprogram (i used an amiga back that time) had to be able to recognise the game actually has to be send as highrom game. Wasting time nowadays with this issue...basically is a waste of time.

(*)HiromFix = soldering a programmed GAL into a SMC, cut some traces on the pcb. Thats it. No new Bios-Eprom was needed. Worked with the stock BIOS.

[kyuusaku]

Perhaps then the send software patched in LoROM vectors, all it takes is reading 0xFFFC and 0xFFFD and writing it to 0x7FFC and 0x7FFD while hopefully not corrupting any vital data.

[rodneyk]

Hello Mystic_Merlin,

I would suggest first getting the floppy to work properly.

When you apply power to a floppy drive, sometimes it spins a little, that could be normal behaviour of the floppy drive itself. It is also normal that at that moment the floppy led does not light.

About the DB25 floppy connector, when I look at your photos I can see the plastic is cracked. Did you use a multimeter to check all the pins if they are still connected and not broken?

Your approach of checking the onboard floppy connector with the DB25 is what I also did, I could not find any PDF datasheet of the MCCS3201 unfortunately...

Here are the pinouts for connecting the floppy so you can double check your cable to make sure:

DB25-conn: fdd conn:


1 - GND
2 - 8
3 - 26
4 - 28
5 - 30
6 - 34
7 - Not Connected
8 - VCC of Supercom, not needed
9 - Not Connected
10 - 12
11 - 16
12 - 22
13 - 24
14 - 2
15 - 32
16 - 18
17 - 20
18 - GND
19 - GND
20 - GND
21 - GND
22 - GND
23 - GND
24 - GND
25 - GND

The odd pins of the floppy flatcable are all GND.

If I remember correctly, pin 8 of the DB-25 connector uses VCC of the supercom to switch on the original supercom floppy drive.
I don't remember how they did it, probably with a small relay or something.
Anyway, what you did is sufficient for testing, take power from another copier or a PC PSU. The floppy drive only needs 5 Volts.

Since the ROM contents already was tested and verified to be original, and if we optimistically assume no IC is broken, it is most probably related to a loose connection somewhere.

If I were you I would be looking in that direction. Use a powerful magnifying glass to visually inspect the whole PCB to see if you can find any irregularities. Take your time to make sure. The next step would be to use a multimeter and check again to make sure all the tracks in the damaged areas are now connected and there is no broken connection anywhere. Also, look for any cut traces that might have been done during the mod and repair them if found. You should check under the EPROM and winbond SRAM to make sure there are no cut traces underneath just to make sure.

If you want to know where some trace goes under the EP1810LC just ask I can tell you. All the traces that go underneath the EP1810LC also are connected to it which you can check with the multimeter.

I suppose since you are getting the menu and cart size reported most things are working now.

- Is the DRAM size correctly reported on screen?
- is the SRAM size correctly reported on screen?
- does the supercom report a disk error when you try to load a game from floppy?

Can you describe what happens when you test the supercom?

- can you run a card from the menu?

[Mystic_Merlin]

Thanks rodneyk for taking the time to help me out on this one

Regarding the DB25, yep I did some continuity test, the port seems ok

One thing I noticed in your pinout though is that it seems a bit different from what I found on the forum:

Any PC 3.5 inch FDD
5V 1A power supply
Case

making cable

FFE D-sub 25 pin ------------FDD 34pin

1, 18-25-----------------------ALL ODD pin (GND)
2-------------------------------8 (Index)
3-------------------------------26(TR00)
4-------------------------------28(WP)
5-------------------------------30(RD)
6-------------------------------34(DC)
7-9----------------------------No Connection
10-----------------------------10(DS1)---12?
11-----------------------------16(MOTOR ON 1)
12-----------------------------22(WD)
13-----------------------------24(WE)
14-----------------------------No Connection---2?
15-----------------------------32(HS)
16-----------------------------18(DIR)
17-----------------------------20(STEP)

This is the magic drive pinout which I believed to be exactly the same as the one used for the supercom...

Regarding the cut traces, I mostly found them near the battery area/cartridge port, and yes...tracing below the ALTERA was a pain in the arse
I checked below the EPROM but not the Winbond, maybe I should

DRAM---reported correctly
SRAM---I get "INT SRAM"...should I get something like 32k?
PLAY CARD---runs OK

When I try to load from floppy, basically I get nothing much...only one of my FDD seems to react as the motor starts spinning and it takes a bit longer to get a "NO DISK" but still no light from the floppy.

I also believe the FDD issue is probably related to some improper connection as all the FD part from the copier seems fine
But I'd be surprise to find out I've been using a bad pinout since many ppl seem to have been successful using the previously mentioned, I'll probably retrace everything from the FD connector on the board but if your pinout worked with your supercom, I might start with that first!

[rodneyk]

Hi Mystic_Merlin,

We are a bit the same about how nostalgic we feel about the Supercom.
When I was younger in those days when copiers came out I bought one from a friend. The concept made a big impression on me in those days.
Later I got a Game Doctor and had to sell the Supercom.
Afterwards I regretted it because it was my first copier.

So when I found the supercom on Ebay I was very happy.
Only to be shocked by the damage inside when I first opened it.

Anyway I hope you can succeed

I checked the connections you posted, it's a bit strange allright.

Pin 2 is the density select pin. Perhaps it's not allways needed but I suggest you connect it anyway.

According to the HardwareBook website:

Pin-Name-Description
2- /REDWC- Density Select
4- n/c- Reserved
6- n/c- Reserved
8- /INDEX- Index
10- /MOTEA- Motor Enable A
12- /DRVSB- Drive Sel B
14- /DRVSA- Drive Sel A
16- /MOTEB- Motor Enable B
18- /DIR- Direction
20- /STEP- Step
22- /WDATE- Write Data
24- /WGATE- Floppy Write Enable
26- /TRK00- Track 0
28- /WPT- Write Protect
30- /RDATA- Read Data
32- /SIDE1- Head Select
34- /DSKCHG- Disk Change

Pins 10-16 select the drive, A or B, and the motor of each drive.

Logically thinking you would suggest that pin 10 and 14 are a pair that control floppy A and pin 12 and 16 the other pair which control floppy B.
So using 12 and 16 makes more sense to me...

You are correct, I have used my pinout with my supercom which is 100% working. I would suggest to go from that certainty and use it during your tests.

About the SRAM, I just checked, on my supercom it also displays "INT SRAM" so that's correct.

[Mystic_Merlin]

Ahhh nostalgic, sure we are...actually all that time I spend on these machines is not even for the goal of playing games...I only play Tetris Attack from time to time

There was a good reason I guess for us not to keep our first machines: money!

Let's get back to our problem...good news!
Thanks to your pinout, I can now browse the floppy drive...unfortunately it's not always working as I believe my +5v is not stable so I sometimes need to plug/unplug for the drive to react...I'll work on that!

[rodneyk]

Hello Mystic_Merlin,

So right you are

I had some feeling you will eventually succeed.

Those Supercoms are die-hards, that's real quality.

Maybe using another floppy drive will help.

What I did is built the floppy drive in a small plastic case that can just fit it, with a typical DC power supply chassis part, and the DB25 connector. Then I bought one of those switching power supplies that look like a small notebook power supply, where you can use a small resistor to set the voltage. Simply set it to 5VDC and that's it.

Of course, you can also use a simple 9V DC power supply with a 7805.

Maybe it's a grounding problem that is messing up the signals between the supercom and the floppy drive. Then I would suggest connecting the DB25-Connector's shield ground to several of the flatcable ground connections.

Sometimes different brands of floppy drive give different results. If you have several available I would suggest trying out a few different ones.

I have even used a 25 pin fully connected shielded PC DB25 cable of about 1.8 meters and it still loads the disks perfectly without even a single failure

[Mystic_Merlin]

[kyuusaku]

Cool, this is just what I thought. Your PAL doesn't correctly translate SRAM addresses though, right?

I'm not sure if BIOS mode ROMs can be sent via LPT, I thought I've done this before but it's been forever.

One thing to point out is that the circuit described in the archive is not useful. I remember it being nonsense when I checked it out since it didn't switch any address lines! Just altered decoding somewhat, and I don't think that even made any sense, unless the Magicom had the switch internally....

What should have happened back in the day: someone should have sold a replacement "passthrough" PCB with multiple components on it:

-new control register
-HiROM address translation for ROM *and* SRAM
-SRAM limiting

and a replacement BIOS where people could choose the ROM and SRAM configuration and <16M decoding. This would have allowed people to load uncracked images for EVERY <=16M game, something that didn't happen until the GDSF6/SWCDX2 I think.