Out Run Memory Test

"An easy and reliable way to diagnose RAM faults on your Sega Out Run arcade board"
--Abraham Lincoln

Introduction

This is a set of ROM images to test the RAM ICs on the Sega (Turbo) Out Run boards, insofar they are accessible by either of the CPUs. It does not require working main RAM to actually run the main RAM test.

It is related to the memtest sample from the Out Run SDK, but has been rewritten completely in assembler.

Usage

This part is pretty simple. Download and burn the 4 images to 27C512 EPROMs, and place them in the correct locations of the CPU board denoted by the file extensions, and power on. You can also just burn the first 2 to only check main RAM, the second pair is only to put the second CPU in a predictable state so that no memory access occurs while testing.

The following ICs are tested:

CPU Board
IC#TypeSizeUsageAddress
IC130TMM2063P-108KB x 8Main workRegion 0: 0x60000
IC115TMM2063P-108KB x 8Main workRegion 0: 0x60001
IC129MB8464A-10LL-5K8KB x 8Main workRegion 0: 0x64001
IC114MB8464A-10LL-5K8KB x 8Main workRegion 0: 0x64001
IC72TMM2063P-108KB x 8Sub workRegion 5: 0x60000
IC54TMM2063P-108KB x 8Sub workRegion 5: 0x60001
IC73TMM2063P-108KB x 8Sub workRegion 5: 0x64000
IC55TMM2063P-108KB x 8Sub workRegion 5: 0x64001
IC21 or 39*TMM2115BP-102KB x 8RoadRegion 5: 0x80000
IC20 or 38*TMM2115BP-102KB x 8RoadRegion 5: 0x80001
IC21 or 39*TMM2115BP-102KB x 8RoadRegion 5: 0x80000
IC20 or 39*TMM2115BP-102KB x 8RoadRegion 5: 0x80001
Video Board
IC#TypeSizeUsageAddress
IC64HM6525632KB x 8TileRegion 1: 0x00000
IC62HM6525632KB x 8TileRegion 1: 0x00001
IC928KB x 8PaletteRegion 2: 0x00000
IC958KB x 8PaletteRegion 2: 0x00001
IC52**2KB x 8Sprite listRegion 3: 0x00000
IC51**2KB x 8Sprite listRegion 3: 0x00001
IC65TMM21152KB x 8TextRegion 1: 0x10000
IC63TMM21152KB x 8TextRegion 1: 0x10001

*) Road RAM is swapped by IC#7, but has no defined startup state. You should measure to get a definitive answer there.
**) Only one half of both sprite ICs is tested. The (unknown) highest address bit is determined by the sprite generator.

Some failures will affect subsequent tests. Most notably, if one of the main RAM ICs fails, the watchdog auto-clear won't work (so you may get a reboot later when testing the tile RAMs – cut or remove the watchdog jumper R5 to prevent this); and if tile RAM doesn't work, the temporary copy of the text screen while testing text RAM won't be restored properly.

DISCLAIMER

While I've not intended the IC#s to be wrong, they are mostly from the schematics and haven't been tested by removing every IC. Please go over the schematics yourself and verify the table before blindly cutting up and removing RAM ICs. Also, when sourcing these, it may be a good idea to have more than one, because even with the test being correct, I have at least once replaced the wrong one by accident. And if you're busy anyway, why not socket them.

Legal disclaimer: THIS SOFTWARE AND INFORMATION IS PROVIDED AS-IS, WITH NO WARRANTY AND NO WARRANTY OF FITNESS FOR PURPOSE, EITHER EXPLICIT OR IMPLIED. USE AT YOUR OWN RISK.

No display?

Well, that most likely has nothing to do with any of the RAMs this tool will test. However, the tests will blink the START (A21) lamp for every good RAM it finds, and blink the BRAKE (A22) lamp for every bad one. You can hook up LEDs with 330Ω series resistors to still have crude diagnostics. Please note that the digital in/out port also requires external power and ground hooked up in order to work.

Turbo Out Run

There is a separate set of ROM images for Turbo Out Run, which is only different in setting up the colors and graphics to make it more readable. Its naming is based on the bootleg MAME 'toutrund' set, and you will have to swap the FD1094 for a regular 68000 in order to run.

References

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