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Posted Fri Jan 13, 2012 2:40 PM
Posted Fri Jan 13, 2012 5:02 PM
Posted Sat Jan 14, 2012 6:21 AM
Posted Mon Jan 16, 2012 4:17 PM
Posted Wed Jan 18, 2012 2:45 PM
Edited by 31336haxx0r, Wed Jan 18, 2012 2:45 PM.
Posted Thu Jan 19, 2012 11:49 AM
NICE! Another Laser 500 user! How did that disk drive work? Just plug it in and the computer will boot it? Is the Laser 500 fully compatible with CP/M?
Posted Fri Jan 20, 2012 2:48 AM
Edited by nippur72, Fri Jan 20, 2012 2:50 AM.
Posted Fri Jan 20, 2012 5:47 PM
Posted Sat Jan 21, 2012 3:50 AM
Posted Sun Jan 22, 2012 8:20 AM
Posted Sun Jan 22, 2012 3:22 PM
I looked through the M.E.S.S. ROM dump I found online. The BASIC keywords have the last character of each keyword ORed with 128 (sets the most significant bit which is not used by ASCII text characters). This takes less room that zero terminated strings. The first character of each keyword is also encoded but I haven't taken the time to figure out how.
Holy cow, this is pure awesomeness! Thanks for the pictures! IIRC VTech used a Microsoft Basic type BASIC that had some nice commands they probably implemented by themselves.
10 A=7196 : REM START ADDRESS $1C1C 20 B=PEEK(A) 30 REM SKIP FIRST CHARACTER OF KEYWORD FOR NOW 40 REM 50 REM PRINT CHR$(B); 60 A=A+1 70 B=PEEK(A) 80 IF B>127 THEN 110 90 PRINT CHR$(B); 100 GOTO 60 110 B=(B AND 127) 120 PRINT CHR$(B) 130 A=A+1 140 IF A < 7851 THEN 20
Edited by JamesD, Sun Jan 22, 2012 3:46 PM.
Posted Sun Jan 22, 2012 3:51 PM
Posted Sun Jan 22, 2012 3:58 PM
If I were to guess, the first character has something to do with the token since the same letter is different from one keyword to the next even though they may start with the same first character.
I should type in that program when I'ma fire ma Laser up again LOL. That's ingenious to use the MSB as a terminator to save space. I wouldn't have thought about that in the first place and neither in the second place.
Maybe they inverted the first characters?
Edited by JamesD, Sun Jan 22, 2012 4:02 PM.
Posted Sun Jan 22, 2012 4:29 PM
While the color palettes of the Laser 500 and CGA may look very close, I don't believe it means they have the same chip.
I too cannot believe they developed a whole freaking video chip from scratch. An address decoder chip, okay. But not a video chip. Let's have a look at the graphic modes:
Given that the Laser 100/110/VZ200/300 (which are TRS-80 Model 1 clones) used the 6847 like the TRS-80 Color Computer, I assume it's their derivative of a 6545/6845/6847.
The Z80 as well as the 8088/8086 are descendants of the 8080. All of those processors use a design that employs "ports" and apparently there is a CP/M80 disk for this computer. Hmm....
Edited by JamesD, Sun Jan 22, 2012 4:31 PM.
Posted Mon Jan 23, 2012 2:38 AM
I'm very curious how they did the video display, whether it's RAM is paged or accessed through ports.
Posted Fri Apr 20, 2012 7:37 AM
Posted Fri Apr 20, 2012 11:24 AM
Posted Fri Apr 20, 2012 12:54 PM
Posted Fri Apr 20, 2012 1:51 PM
Posted Wed Oct 10, 2012 2:27 AM
Well, it took some 8 months or so for the computer to travel 200 km but finally it is here. A brief test shows it powers on, but the picture in in B&W both through RF and composite video. It has an AZERTY keyboard so I suppose it is a SECAM edition. My previous experiences with SECAM have only been through RGB, so perhaps it is perfectly normal that not every monitor can display colour? I only tried a 14" Luxor TV and a 1084. I have many more TV's and monitors to try, including those who happily chew NTSC composite video, but perhaps the ability to display NTSC wouldn't matter to the ability to display SECAM?
Since a couple of months ago, I'm having a Laser 500 in a carrying case waiting for me to pick it up.
Posted Wed Oct 10, 2012 8:51 AM
Posted Wed Oct 17, 2012 9:52 AM
Posted Thu Nov 1, 2012 2:40 PM
Edited by carlsson, Thu Nov 1, 2012 3:10 PM.
Posted Thu Nov 1, 2012 2:58 PM
Posted Thu Nov 1, 2012 3:22 PM
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