Peter's z80.eu site blog
It's a real nice (but heavy) "portable", the IBM PS/2 P70 - build 1989 'til 1991 
Sunday, October 30, 2016, 01:03 PM
Posted by Administrator
A real beauty, this IBM PS/2 P70 - a 386 based machine with an ESDI harddrive.

But also a delicate device, because meanwhile the floppy drive often could make problems (can be related with capacitors on the floppy drive board) and also the ESDI drive is NOT unproblematic. If you run SCANDISK (from MS-DOS 6 or later), and if you get after each program run loop more and more bad clusters, you have "disk snow". This means your drive is dying slowly. Also, trying to low level these ESDI drives is NOT easy, you should NOT use drive manager software for this task. There is a special setup floppy disk for this purpose, and there is a secret key for entering the low level format menu (press Ctrl-A within the normal diagnose main menu). But even then it could fail (this happened for my try). Can be related with the "bad sector table" which should be existing for each ESDI drive. Don't know an other reason, because otherwise if the drive controller is faulty, I would get errors while loading/saving files. But all things saved on hard drive works smoothly (no errors). Regardless of that, also the display can make problems.
The plasma display is - if it works - not too bad, see the second picture driving "Pole Position II"...

Last but not least the keyboard is excellent, similar to the famous "clicky" IBM PS/2 keyboards for the IBM desktop computers (but a bit more compact).

See "related link" for a related site / a source for the setup & diagnose disk for the P70.

add comment ( 2 views )   |  permalink   |  related link   |   ( 3 / 113 )
Forgot to mention SARGON 4 as part of my chess program overview... 
Wednesday, September 21, 2016, 08:30 PM
Posted by Administrator
Very nice, and runs with CGA, EGA and VGA cards: Sargon 4 (and not Sargon IV), distributed by Spinnaker Software, not from Hayden Software (which published the famous first three Sargon versions). It's playing good, although different from Sargon III, which is not surprising because it's from a different software developer.
It looks in all three possible display modes good, see yourself:

CGA

EGA

VGA

See wikipedia also for additional infos about the Sargon series (related link below).
Other chess programs are shown and listed in my 4 part blog series, --> last part here
add comment ( 3 views )   |  permalink   |  related link   |   ( 3.2 / 405 )
Finally an exploding capacitor was occuring again (this time: Kaypro II) 
Wednesday, August 31, 2016, 11:50 PM
Posted by Administrator
Yeah, hate this. While I tried to copy Kaypro II floppy disks in my PCs (with TELEDISK first, but then with 22DISK, and with many read retries), I thought it would be much easier to copy them with my Kaypro II itself. Just power it on, boot with CP/M 2.2, start COPY, and then the copy session for about 10 disks was started.
But guess what happened - it makes an ugly "Poff" sound and then it stinks forbidding.
The capacitor for avoiding interferences from the power supply line, a 0.22 uF "film" one, exploded and burned a bit too. I switched immediately the computer off and carried it to outside the house (... still stinking).
Then I opened the case, dismounted the mainboard, then the power supply itself:

This was the capacitor after explosion:

After I buyed a new capacitor and after repair it looks now like this:

And after reassembling most of the parts, it runs (without stinking) again, hurray:

There were some other capacitor candidates for a later replacement, but I was happy it runs again.... the Kaypro II and its power supply was MUCH EASIER to repair compared to the nightmare with the Macintosh IIci. See "related link".
add comment ( 6 views )   |  permalink   |  related link   |   ( 3.4 / 811 )
Advertisment IBM Portable PC and two other early portable PCs 
Monday, August 22, 2016, 06:25 PM
Posted by Administrator
These advertisments in the eighties were not very plausibly, but not only IBM published PC Ads in that manner. That man couldn't really look onto the screen and was able to read anything. See and judge for yourself:

But it was IBM's necessary answer to the Compaq Portable PC, a bit late, yes.
And it's a beauty meanwhile. Other portables looked more ugly.

Corona Data Systems and also Sperry Corporation (in fact, it was the same computer with different labels) selled early portable PCs. This is a picture of the "Sperry Portable Computer", which is meanwhile a real rare Portable PC (still looking for an affordable one):

It was selled from late 1984 until Sperry Corporation was merged with Burroughs in 1986.
It doesn't have an amber screen (like the IBM Portable PC), instead, a green one with 9 inch size. An Intel 8088 with the same speed like the first IBM PC and 256KB RAM (expandable to 512KB on motherboard) was included.

See also in related link for an article in "Infoworld", November 1984.
add comment ( 10 views )   |  permalink   |  related link   |   ( 3.2 / 981 )
BASIC game classics... today: CAMEL (slightly improved version of the original David H. Ahl source) 
Sunday, July 31, 2016, 08:15 PM
Posted by Administrator
Do you remember the times games only shows text messages ?

David H. Ahl was the editor of two real famous books: "BASIC COMPUTER GAMES" and "MORE BASIC COMPUTER GAMES" in 1979, published from "Workman publishing, New York".
One of these games I remembered was "CAMEL". It just shows up a few text messages and you can enter a small range of numbers as a command what to do next (after the game started).
Of course the whole program flow was controlled by the random generator, you will NOT often win.
But it was fun to beat the computer... at least if you would reach the 200 miles limit.
The game source was slightly improved, e.g. displaying the status was decreasing life points (so I changed this, it will not decrease life points anymore and I added a help display).
I didn't changed the original program logic, so it's still not easy !

This is how it looks (game is just started):


You can get the BASIC SOURCE CODE if you click on "related link".

Good luck while playing the game.
add comment ( 12 views )   |  permalink   |  related link   |   ( 3.1 / 1270 )

| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Next> Last>>