Description
The Sorcerer was an interesting combination of parts from a standard S-100 bus machine, combined with their custom display circuitry. The machine included the Zilog Z80 and various bus features needed to run the CP/M OS, but placed them inside a "closed" box with a built-in keyboard similar to machines like the Atari 8-bit family and Commodore 64. The rest of the S-100 expansion capabilities were instead to be provided in an external box.
Even the basic machine was usable on its own, an advantage over other S-100 machines. It included a small ROM containing a simple monitor program which allowed the machine to be controlled at the machine language level, as well as load programs from cassette tape or cartridges.
With additional hardware plugged into the S-100 bus (actually a dual-50-pin connector on the back of the machine) the Sorcerer could directly support floppy disks, and boot from them into CP/M (without which the disks were not operable). Another expansion option was a large external cage which included a full set of S-100 slots, allowing the Sorcerer to be use like a "full" S-100 machine. Still another option combined the floppies, expansion chassis and a small monitor into a single large-ish box.
Graphics on the Sorcerer sound impressive, with a resolution of 512 x 240, when most machines of the era supported a maximum of 320 x 200. These lower resolutions were a side effect of the inability of the video hardware to read the screen data from RAM fast enough, given the slow speed of the machines they would end up spending all of their time driving the display. The key to building a usable system was to reduce the total amount of data, either by reducing the resolution, or by reducing the number of colors.
The Sorcerer instead chose another method entirely, which was to not really to have graphics at all. Instead they allowed the user to re-define the character set (the shapes of the letters on screen) and used these in lieu of pixel-addressable graphics. In fact the machine was actually drawing a 64 x 30 display (8x8 characters) which was well within the capabilities of the hardware. However this meant that all graphics had to lie within a checkerboard pattern on the screen, and the system was generally less flexible than machines with "real" graphics. In addition, the high resolution was well beyond the capability of the average color TV, a problem they solved by not supporting color. In this respect the Sorcerer was similar to the PET in that it had only "graphics characters" to draw with, but at least on the Sorcerer you could define your own.
Given these limitations, the quality of the graphics on the Sorcerer were otherwise excellent. Clever use of several characters for each graphics allowed programmers to create smooth motion on the screen, regardless of the character-cell boundaries. A more surprising limitation, given the machine's genesis, is the lack of sound output. Enterprising developers then standardized on attaching a speaker to two pins of the parallel port, which users were expected to supply.
Another item of note on the machine was the excellent keyboard, which suggested it was more of an "upscale" machine competing in the S-100 world than the average home computer. It was well built with considerable "throw" to the keys, and also included a numeric keypad. The keyboard included a custom "Graphics" key, which allowed easy entry of the extended character set, without having to overload the Control key, the more common solution on other machines.
The included Standard BASIC was essentially the common Microsoft BASIC already widely used in the CP/M world, but Exidy added a number of one-stroke commands that allowed you to type in common instructions, like PRINT with a single keystroke. The machine included sound in/out ports on the back that could be attached to a cassette tape recorder, so BASIC could load and save programs to tape without needing a disk drive. An Extended BASIC requiring 16k was also advertized, but it is unclear if this was actually available.
Specifications
- CPU: Zilog Z80, 2.106 MHz (later 4MHz)
- RAM: 4k, expandable to 48k. larger sizes came standard in later runs
- ROM: 4k, cartridges could include 4 to 16k
- Video: 64 x 30 character display, monochrome
- Sound: none (external additions possible)
- Ports: composite video, Centronics parallel, RS-232, sound in/out for cassette use, 50-pin ribbon conncector including the S-100 bus.
External links:
- Trailing Edge's Exidy Sorcerer Pages
- Mike's Exidy Sorcerer (Z80) Page
