Specterm-64 v4.0 – Timex/Sinclair Computers

Ed Grey Enterprises

Grey & Clifford Computer Products

Date: 1986

Type: Program

Platform(s): TS 2068

Specterm-64 is a 64-column terminal program for using the TS2068 with a modem over an RS-232 interface. The sign-on screen reads “SPECTERM-64 TERMINAL PROGRAM / 1986 G&C COMPUTER PRODUCTS / VERSION 4.0”, with a copyright notice in the name of Stephen Adams, and “G & C COMPUTER PRODUCTS L.A., CA”. Text shows 64 characters per line using the program’s own narrow character set. A status line shows the mode and settings, a command line offers its options (COMMAND RET,SP, ,O,E,B,R,T,L,S,C), control characters are sent by typing a letter A–Z at a prompt, and text can be kept in a buffer saved under the name TEXT.CODES.

The BASIC loader, SPTLOAD, is “SPECTERM-64 OVERLAY LOADER VERSION 1.0 ©1986 DAVE CLIFFORD & ED GREY”. It asks for the serial interface in use and loads the 3,242-byte terminal program (SPTERM, at 30806) followed by a small driver overlay for that interface.

Program Analysis

Interface Overlays

Each overlay is 47 bytes loaded at 33872, inside the area of the main code, so it replaces the driver part of SPTERM. The overlays differ only in the port numbers they use:

WC2050: a stock Timex TS-2050 modem (ports 115 and 119).
2050zx: a modified TS-2050 (ports 63 and 127).
Z-SI/O: the standard Z-SI/O interface (ports 159 and 191).
Z-SI/Ojlo: a Z-SI/O readdressed to work alongside a JLO (Oliger) disk system (ports 215 and 223).

Each holds the routines to read status, read and write a character, and a set-up sequence that resets and programs the interface’s serial chip.

Loader Menu

1: SAVE COPY of Specterm 64 with the new overlay: saves SPTERMLD and the code, so a copy already set up for one interface can be made (the overlay lies inside the 30806–34047 range that is saved).
2: RUN Specterm 64 (RANDOMIZE USR 30806).
3: EXIT to BASIC.
4: DISCONNECT (2050 only), which sends OUT 119,0 to drop the line.