Editor’s Note: In TSH #11 John answered hardware questions on the TS1000, but as you can see below he is versed on the software side also. TS Help and Information has the potential to be very helpful, but it can’t continue unless we get more questions from our readers. John is also very familiar with the TS 2068, by the way.
Question about PEEKs
I have been trying for sometime to find out the necessity of making a statement such as the following:
LET X=PEEK 23631 + 256 * PEEK 23632 What is the reason for the ” + 256″ and does the computer actually multiply that number by the next address?
Erich Best
Largo, Florida
Most of the time this statement is used to find out the start of an address which is stored in two bytes, such as the start of the display file. To explain further, take the address 16514, To put this address in two byte form, you first divide the 16514 by 256, and take the integer value of that number; this is your first and most significant byte, or MSB. To get the second byte and least significant byte, multiply the MSB by 256 then subtract it from the number you started with; 16514-(256*MSB)=LSB; 16514-(256*64)=LSB; 16514-16384=130, Now our LSB is 130.
Now to return the number back to normal, do the following:
LET X=LSB+256*MSB or LET X=130+256*64; X=16514.
TI-99 Keyboard Project Planned for Next Issue
For those of you who haven’t heard Radio Shack is offering a surplus keyboard from the TI home computer. This keyboard makes an excellent addition to your ZX81, TS 1000, or even the TS 1500. Although the keyboard must be re-wired, it is well worth the three dollars’ yes, you read right, only three dollars. This is a far cry from the ten to thirty dollars for an unwired keyboard available from other sources. Next month I hope to have plans for wiring up and installing this keyboard to your computer. I am in the process of doing mine now. If you were unable to get one of the keyboards from Radio Shack, a surplus company in Florida is offering the same one for six dollars. This is still a bargain.