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Lomas Data Products  - Color Magic Video Board
This was a fantastic board when it first came out.  It was at the time when the IBM-PC was beginning to dominate the PC market and CPM 80/86 software was moving in mass to the PC-DOS platform.  While many manufactures could get their S-100 systems to be compatible on a text/disk I/O basis with PC-DOS on the IBM-PC, what was absence was the ability to do graphics and accept a true IBM-PC keyboard with an interrupt controller etc..  Lomas (as I remember it anyway), were the first to address this need with this board.

LDP Color Magic Board

The board was densely packed with IC's but was easy to setup.  The was designed specifically to bring the wide range o£ software available for the IBM-PC to the S-1OO bus. With this board and the appropriate software the majority of software available for the IBM-PC including software that wrote directly to video RAM and the hardware control ports of the IBM-PC could be used with most high performance 8086 type CPU boards.

There are several issues in emulating the IBM-PC, the first is hardware compatibility. The ma]or hardware items of the IBM-PC which must be considered in an emulation are as follows:
 
1.  The microprocessor being used.
2.  The floppy disk controller hardware.
3.  The display hardware.
4.  The keyboard hardware.
5.  The timer hardware.
6.  The I/O hardware (i.e.  RS232 and Printer ports etc.)

Each of these issues were addressed by LPD in the manual below.

The I/O ports of the board were assigned to correspond to the port assignments of the IBM-PC for the corresponding functions.
The following is a list of device addresses on the COLOR MAGIC board:
 
Hex Adderss
Register Function
40
41
42
43
60
61
62
63
3D8
3D9
3DA
3DB
3DC
3D0-3D8
8253 TIMER 0
8253 TIMER 1
8253 TIMER 2
8253 TIMER CONTROL PORT
8255A PORT A
8255A PORT B
8255A PORT C
8255A COMMAND PORT
MODE CONTROL REGISTER
COLOR SELECT REGISTER
STATUS REGISTER
CLEAR LIGHT PEN LATCH
PRESET LIGHT PEN LATCH
6845  DISPLAY CONTROLLER REGISTERS

Through jumper selection the above ports could be relocated to any one of 64 different base addresses. When readdressed, IBM-PC compatibility was of course lost. All port addresses are moved as a group and have an offset of multiples of 400H added to the above address.

A fairly detailed manual was supplied. It can be obtained here.
The schematic for this board can be obtained here.
  

 

Other LDP  S-100 Boards
Color Magic     Hazitall     Lightning One   RAM67   FDC   Thunder 186    MEGARAM 

 

This page was last modified on 06/26/2016