With this minor annoyance now solved, I have been happily using Memdisk; that is, until Allen Jacobs asked me if I'd ever heard of a utility called GRAFDISK!

GRAFDISK is written by William R. Bowman and is available on TRSLINK #26 (December 1989) in a file called GRAFDSK/ARC.

For the readers not familiar with files having the /ARC extension, let me just mention that this type of file cannot be used directly. It is usually a collection of files saved In compressed format into one file and, before the files are usable, they have to be 'DEarced'; that is, they have to be restored to their original format. This can be done easily with another program available from TRSLINK, called DEARC4V2/CMD (#21, July 1989).

If you only have two drives, you will have to make room on your boot disk for both DEARC4V2/CMD and GRAFDSK/ARC, and then copy these files from the TRSLINK disks in drive :1 to the boot disk in drive :0.

You can now issue the command:


This will copy the following eleven files to the data disk in drive :1.





Of these files, GRAFDISK/DCT, GDLOAD/CMD, GDSAVE/CMD and SWAP/CMD will be of immediate inter-rest to us.

GRAFDISK/DCT is the all important one here. It is a driver that completely replaces MEMDISK/DCT when setting up a memory disk drive. This new driver does everything that MEMDISK/DCT does. What makes it more powerful is, that if you have a hi-res board installed in your Model 4, it lets you use the hi-res board memory in addition to the 64K in banks 1 and 2. In the case of a Radio Shack hi-res board, it is an extra 32K, giving you a 96K memory disk drive. The Micro Labs board adds only 24K, but that still gives you an 88K memory drive.

If you don't have a hi-res board, don't stop reading now, you can still use this driver. Of course, you won't get the added memory, but you can benefit greatly from the two utilities, GDSAVE/CMD and GDLOAD/CMD.

Copy GRAFDISK/DCT to the boot disk in drive :0 and then issue the command:

Your screen will now display the following prompt:

[C] Disable GrafDISK

Your choice ?

If you have a graphics board installed, choose B, otherwise choose option A.

You will now be asked:

Answer 'Y' to format the Memdisk (now called GrafDISK). After the format has been verified, you will be told that 'GrafDISK Successfully Installed'.

If you are working with LS-DOS 6.3.0 you are now in business. Depending on the presence of a hi-res board, you will have a memory disk drive of either 96K or 64K.

However, if you are using LS-DOS 6.3.1, you will have noticed that the driver does not work. The problem is GRAFDISK/DCT was written to work with LS-DOS 6.3.0. When LS-DOS was upgraded from 6.3.0 to 6.3.1 the system code became slightly larger and, unfortunately, it GRAFDISK/DCT now overwrites part of SYS8/SYS.

As LS-DOS 6.3.1 is now the standard DOS for Model 4, a fix was needed, and this fix can be found on TRSLINK #31 (May 1990). It is a BASIC program, written by L. E. Evans, called GDMOVE/BAS. Running this program will patch GRAFDISK/DCT to load at 3000H, and it will now work with both LS-DOS 6.3.0 and 6.3.1.

I encountered a problem when I tried to run GDMOVE/BAS. BASIC stopped and told me there was a syntax error in line 20. Indeed there was, and a very deceptive one at that.

At the end of the first line, the command 'PRINT' is wrapped around to the next line. Somehow, the TRSLINK text editor inserted a blank between the PRI and the NT.

This also occurs in line 30. Same problem. At the end of the first line, the command 'PRINT' is wrapped around to the next line. The blank is inserted between P and RINT.

Edit out the two blanks and the program will now correctly patch GRAFDISK/DCT. The syntax errors may be unique to my copy of the TRSLINK #31 disk, but just in case it is not, you now know what to do.

It is obvious why you should go through all of this trouble if you have a hi-res board installed - getting 32K (or 24K) of extra memdisk space allows more utilities or programs to reside there. In my case, I now have EDAS, TED and a disassembler up there and, boy, execution is fast.

What is not so obvious, however, is why you should go through the above trouble in order to use GRAFDISK/DCT if you do not have a hi-res board installed.

The key to why you should use GRAFDISK/DCT, even if you do not have a graphics board installed, is the two utilities, GDSAVE/CMD and GDLOAD/CMD. Read on!

The easiest way to set up a MEMDISK or GRAFDISK is to write a/JCL file to send all the commands to DOS, rather than typing them yourself each time you boot.

My STARTUP/JCL file to initialize the GRAFDISK in my 2-drive Model 4P with a Radio Shack hi-res board and a 15 meg hard drive (partitioned into 4 logical drives) is:


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