Having done well in the calculator and Pong system markets, APF needed a system to compeat with the Atari VCS (2600). Like Bally and Mattel (Intellivision) they thought that a system that expanded into a full computer would be a sure winner.
Thus the APF MP 1000 was born, and a year later the IM-1 Imagination Machine computer expansion.
For a history of APF and the man who designed this system, see the article Ed Smith And The Imagination Machine at FastCompany.com
|CPU||Motorola 6800 @ .9 Mhz|
|Video chip||Motorola MC-6847 Video Display Generator|
|Text Modes||32x16 with 2x2 'semi graphics' in 9 colours (8 +Black)|
|Graphic Modes||256x192 in 4 colours 128x192 in 8 colours *|
|Sound||One voice 5 octives|
|Controls||two non removable 4 direction joysticks with 12 key keypad and 1 fire button.|
|Rom||Built in game (4k?) Rocket Patrol|
APF uses the same Motorola MC-6847 VDG as the TRS-80 COCO, Dragon computer, and NEC TREK. But does so in a different way.
Like the NEC Trek, the APF dosen't use the SAM memory manager to drive the VDG. It uses it's own memory management system.
On the COCO, or any normal system a 256x192 graphic mode would need 6K of ram. (256/8 = 32bytes per line * 192 lines = 6144Bytes or 6K). However, the MP 1000 has only 1K of RAM available.
What APF does, is use the first half of that RAM (0-511) as a 32x12 character table. Much like the text mode. It then uses the other half (512-1023) as a character description table of 32, 8x16 highres or 4x16 colour characters.
This introduces some limitations, like not being able to display a full screen bitmaped image, but also makes it much simpler to manage game graphics.