MAMEWorld Forums - EmuChat - time for PSE Desert Patrol mini thread *edit*

*Burying this within the Bazooka games thread rather than starting a new thread since it is also a PSE game.*

For those that have seen data images for Bazooka and wonder how they were generated, it would likely be from Marc Lafontaine's program called Ripper which can be grabbed from here as a zip file attachment. The zip file also includes same instructions I typed here for how to view PSE game images and an image of airplane targets from Desert Patrol.

Marc Lafontaine contributed to MAME during MAME's early years such as this entry for release .13 from 1997.

0.13
----
- Marc Lafontaine submitted a new palette for Zaxxon.

The program has capability of viewing images off of some roms of 1970s and some 1980s era arcade video games. For an example of describing how to view images of either PSE Bazooka or PSE Desert Patrol, load a file where it says file1 and press CP. Set the width to 32 and in the algorithm you have to change the bits to reverse order.

The 'change the bits to reverse order' might not make sense, but what this means is the user presses the algorithm button and then a different screen appears. User presses the Clear button, and after doing that then click on number buttons in direction of going from right to left side (ie 'reverse orer').

Once that is done, then press okay, then set width to setting of 32 and then press the CP button while Desert Patrol's file 'L4' is loaded as file1.

The images of various airplane targets will then appear on the screen, but in an upside down position. The upside down snap image, can be fixed by using a paint editor program to have the image rotated to a right side up position.

Desert Patrol airplane images used to be shown on Dave Widel's website for many years until the web site closed. The example typed above is how dwidel created the airplane target images of Desert Patrol.

roms/proms for PSE Desert patrol are documented in MAME, but it is an incomplete set at this time. A complete working set will still be needed.

The airplane images come from Prom 1 location 4L of Board 2 of Desert Patrol.

If curious as to what Desert Patrol uses, here is a brief description, (now also documented in MAME source code) of what each prom does, what board holds the prom, and prom location, and chip type of rom on each board. This is from Desert Patrol manual and is also in MAME source code.

Desert Patrol Board 1:

chip type is either 82s181 or 6341-1

Prom location at D2: game computer program code
Prom location at E2: game computer program code

Desert Patrol Board 2:

chip type is 6341-1 or 82s141

Prom 1 circuit at location L4: contains target aircraft images and explosion image
Prom 2 circuit at location L1: contains various positions of the parachute and falling man

chip type is either 82s123 or possibly 6331-1

Prom location at H7: contains prom address codes and image speeds.

Each image has its own speed and address block in the image prom.

Desert Patrol Board 3:

chip type is 8574

Prom location at D1: data in prom is organized to produce the waveform of a human scream

To summarize: Board 1 has 2 proms, Board 2 has 3 proms, and Board 3 has 1 prom.

So Desert Patrol has 6 proms total across three different pcbs.

The hardware of both Desert Patrol and Game Tree are actually same hardware layout as described by the Game Tree manual. Probably the same for PSE Bazooka, but I have never seen nor read Bazooka manual, but only its logic schematics that are online.

Edited by gregf (11/23/14 09:47 PM)