A week ago, I had the honor of receiving number 20 of 20 pre-released models of the FD-68 Disc Drive System for the Timex/Sinclair 2068 from Aerco, for review. After a bad experience with trying to obtain the Millennia K Disk Drive Interface from Ramex (see accompanying article), I was leary of looking at an incomplete disc operating system (DOS), but I was pleasantly suprised. (Editor’s Note: Aerco will be releasing updates for the interface board as improvements are made. Simply replacing the socketed EPROM is all it takes. Aerco will provide the updates free. In fact, right after our review unit was shipped, we received the first EPROM update. Eventually, the FD-68 will contain all of the extensions, and a proposed Spectrum mode.) The main commands to operate the system are:
FORMAT "", ......... to format disc
MOVE "n.X", ..... to save to disc
CAT "n.X", ...... to load
ERASE "n.X", .... to erase program
from disc
CAT "", ......... to call disc
catalog menu
n = name of program (1 to 10)
x = extension as follows:
.ARO - refers to dock bank
.BAS - basic program
.BIN - binary data (machine code program)
.BUT - boot program to be executed at
start up
.CHR - character array
.DAT - numeric array
.LRO - LROS runs in dock bank starting
at 0
.SCR - screen is a copy of the video
display
Examples: CAT "tasword.BAS",
MOVE "zeus.BAS",10
MOVE "zeus.BIN",#,#
# = start and length of MC
The system comes with an interface that is 4 inches tall by 6 inches long with through edge connector for other add-ons. There is also a boot disc and a 2/3 height Remex drive in a case (6 5/8″ X 7″W 10″L), with a power supply on the end, extending the lenghth to 13 inches. It appears that there is room in the case for two additional drives, although the power supply and ribbon connector are set up for two maximum.
I also set up my Tandon 100-2A disc drive following Aerco’s instructions in their literature. A jumper wire had to be installed from the + 5v power supply to pin 2 of the disc drive’s edge connector, and a jumper from + 12v to pin 34 of the same edge connector.
The following is a comparison of the features between two disc drive interfaces available for the T/S 2068:
RAMEX AERCO 1st drive QUAD density any memory used 4 to 8k RAM ROM approx. speed 32k/sec 8.6k/s syst. cost (do $450 $380 it yourself) to be useful... 2 drives 1 drive
Some searching and loading times:
Tasword II ............... 5.7 sec. Zeus Assembler ........... 3.5 sec. A 37.6k BASIC program I wrote that loads from cassette tape in 3 min. & 14 sec. ................ 4.87 sec.
On a double-density, double-sided disc, you have 400k of memory storage. I believe that with the 64k additional RAM in 8k bank switching, the RGB output port, and the DOS on ROM, make this system the best buy for your money. In the next issue of TIME DESIGNS, I will give further information on the Aerco Disc Drive I/F.
System available from: AERCO, Box 18093, Austin, TX 78760. Cost: Interface-$199, Drives- $99 each, Power Supply/Case-$99. CP/M Boot Disc will be available soon for the FD-68 (Kaypro/Osborne version).