Category Archives: basic

PCem ported to FreeBASIC

Posted on by
6

Yes, it’s that PCem. And yes BASIC.

From the post on the freebasic.net/forum.

Some time ago I raised a challenge: make a PC emulator 80486 in Basic !!!

To achieve this, I used a very old version of PCEM, with the help of “FreeBasic”, starting from PCEM-V4.1, about six months ago, I managed to make it work, in 80286 mode only. Then I went little by little adding functionalities of the following versions, until arriving at the V8 (not completely, but if great part). Due to the complexity and lack of speed in BASIC, I have only converted the modules that have interested me the most, eliminating many unnecessary ones, so I have managed to reach an 80486-DX2-66mhz with FPU, 16mb of RAM and VGA TSENG of 2mb.
I have removed many non-necessary modules, such as the sound (it does not have any sound), the LPT port, the PS2 port, the FDC unit and more.
It has many faults, but in general they work VERY well, and it is capable of running “WINDOWS 3.11”, “Deluxe Paint”, “Wolfstein 3D” and many other programs. 
It can reach a resolution of 800×600 to 16 colors, but it moves better in 640×480 16 colors.
The keyboard fails, all the keys do not work, and neither EMM386.EXE nor EXPANDED memory can be used, because it fails and becomes very slow.
It works in both protected mode and real mode, but when entering protected mode, the PC becomes slow.

It’s slow, but yes, it runs!

It only has one config hard coded, as jepalza ported enough of it for this one config. Oddly enough it’s my least favorite the ‘winbios’ 486.

I have to say this is pretty cool!

As always, here is my mirror (usual 404 page reading required) here: PCEM_FB486.rar

Booting a PC over serial port via ROM Basic!

Posted on by
2
Galaxian via Basic over the serial port

I was sent this link while out for vacation: https://github.com/retrohun/blog/tree/master/dt/bootingfromcom1

So this is great for machines that included the seemingly useless ‘casette basic’ as you could maybe shove over something to config the machine, maybe ‘rom dos’ directly into ram to fdisk/format without using disks… Interesting stuff to say the least!

Soon

Posted on by
14
Microsoft Game Studio

I’m on an extended work trip, so I’ve been unable to do much of anything blog like the last few weeks. But as a bonus I have about 6 months worth of random crap from Ebay packed up to take back to Hong Kong to review.

And yes, It’s nearly been a year in the making for this one, but rest assured unless the disks are un-readable this will happen!

Otherwise, the Diablo thing with the release to mobile only went over like a proverbial lead balloon.  Kind of gutsy to host a convention to die hard PC fans and try to keynote on a re-skinned rip off phone app, that’s just been accepted as now ‘official’.  Talk about outsourcing gone wrong.

UPDATE: sad news I have a piece of luggage MIA.  This may not be happening now. 

UPDATE2: Bag showed up, loaded the disks, and after 7% of disk one, my 5 1/4″ drive just died.

:'(

Microsoft XENIX 286 BASIC Compiler

Posted on by
12

(This is a guest post by Antoni Sawicki aka Tenox)

I have recently acquired this artifact:

It’s the Microsoft BASIC compiler for XENIX 286 Operating System. Compiler as opposed to just BASIC interpreter, it can produce executable a.out files, similar to C compiler for example.  

Carefully removed the shrink wrap. Inside were couple of 5.25″ floppies, registration card and a manual:

Interestingly the 32 year old disks read just fine on a first attempt. I need to start backing up important files to 5.25″ floppy disks as they seem to outlast everything else.

Thanks to efforts of Michal Necasek from OS/2 Museum now you can run Microsoft XENIX 286 in Virtual Box. 

The disks can be installed in to XENIX running on Vbox following a few simple steps:

tar xvf /dev/fd0
./msinstall /dev/fd0

Upon installation you invoke the compiler like this:

bascom demo.bas
./a.out

And it produced an a.out executable which worked perfectly fine.

It’s fun to write BASIC code in vi editor, which I just realized I never done before.

Curiously the compiler also worked on the brand spanking new Xenix 2018, or rather I should call it Open Server 6, which you can download here.

The BASIC compiler is available for download from my archive along with the manual in pdf.

Building the Original Commodore 64 KERNAL Source

Posted on by
1

I just found this post over @pagetable.com, the source code to a bunch of old Commodore 8 bit products have been located and recovered, and place online over on github.  Even better there is detailed instructions on cross assembling from a suitable PET machine for building your own KERNAL ROM.

Other sources include:

  • BASIC_C64 reindented BASIC_C64, KERNAL_C64 and DOS_1540 to approximate the LST
  • BASIC_CBM2_A reindented BASIC_CBM2_[AB], KERNAL_CBM2_[AB] and EDITOR_CBM2 to appro
  • BASIC_CBM2_B reindented BASIC_CBM2_[AB], KERNAL_CBM2_[AB] and EDITOR_CBM2 to appro
  • BASIC_PET2001 added BASIC_PET2001
  • DOS_1540 reindented BASIC_C64, KERNAL_C64 and DOS_1540 to approximate the LST
  • DOS_1571 added DOS_1571
  • DOS_1581 added DOS_1581
  • DOS_4040 reindented DOS_4040 to approximate the LST output of the assembler
  • DOS_8070 reindented DOS_8070 to approximate the LST output of the assembler
  • DOS_8250 reindented DOS_8250 to approximate the LST output of the assembler
  • DOS_D9065 reindented DOS_D9065 to approximate the LST output of the assembler
  • EDITOR_CBM2 reindented BASIC_CBM2_[AB], KERNAL_CBM2_[AB] and EDITOR_CBM2 to appro
  • KERNAL_C64_01 added KERNAL_C64_03 and renamed the existing KERNAL_C64 to KERNAL_C64_01
  • KERNAL_C64_03 fix disclaimer of C64 KERNAL -03 to reflect the LST printout
  • KERNAL_CBM2_A reindented BASIC_CBM2_[AB], KERNAL_CBM2_[AB] and EDITOR_CBM2 to appro
  • KERNAL_CBM2_B reindented BASIC_CBM2_[AB], KERNAL_CBM2_[AB] and EDITOR_CBM2 to appro

Super late, but pretty cool too!

Of interest is the PET2001 Basic sources.  While there have been reversed efforts dating back for years, this is the actual source code.  Namely the header.


TITLE BASIC M6502 8K VER 1.1 BY MICRO-SOFT
SEARCH M6502
SALL
RADIX 10 ;THROUGHOUT ALL BUT MATH-PAK.

$Z:: ;STARTING POINT FOR M6502 SIMULATOR
ORG 0 ;START OFF AT LOCATION ZERO.
SUBTTL SWITCHES,MACROS.

REALIO=4 ;5=STM
;4=APPLE.
;3=COMMODORE.
;2=OSI
;1=MOS TECH,KIM
;0=PDP-10 SIMULATING 6502

Which is pretty damned interesting. The infamous “WAIT6502,1” feature is also included!

Commodore Lemonade

Posted on by
4

Simulations before the sims

Lemonade on the PET

Back before there was sim city, the first popular simulation thing I can think of on our ancient basic bound 8 bit machines (and even mainframes running basic!) was Lemonade.  Wikipedia, naturally is full of Apple citations, and of course, is absent of any mention of the most popular selling home computer of all time, as Commodore is usually scrubbed from history in favor of this narrative that Apple was some how popular (it wasn’t).

Oddly enough tracking down these older versions of Lemonade is really hard.  But thankfully others have done the hard work for me!

First from The Sleeping Elephant,  and here is lemonade!.prg for the Pet microcomputer.  It’ll run fine in Vice, although it’ll run best using a Pet 3016 – 3032 and the model 4016 and 4032.  It needs more than 8kb of RAM, so the original models are out, and the ‘graphcis’ don’t display corrrectly on the larger 8000 models, although the game does run.

But what about the Commodore 64?

Commodore Educational Software

By the time the Commodore 64 came out, Commodore had stepped upped their game, and made available a large number of basic programs ported to the Commodore 64. As always the thinking is if you can convince parents that this is educational and it’ll help their kids, they’ll buy one.  Well in this case they were right!  Although lacking the cool animation of the PET, it does include more documentation.  And thanks to vcfed.org, You can download a tape file image here.

Game Play

Unsurprisingly the game play is pretty much the same.  You buy your Lemon concentrate, sugar and cups, try to predict demand based on your price and the weather.  You set a price, and sit back and hope for the best.

Lemonade Stand on the PET

Lemonade Stand on the Commodore 64

Once you figured out that the first few lines (3-5 on the C64) were there to not let you alter it, you were golden.  With the source, you could make summer last 10 years if you wished, or change any of the seemingly arbitrary limits.  If you were really keen on it, you could also print the source code and work out the logic flow with a pencil, something that you really needed back in the days of 40 column screens.

Settings -> Virtual Device Traps

Settings -> Drive Settings -> (Uncheck) True drive emulation

Settings -> Peripheral Settings

And now you can click the printer #4 tab and set it to output a to a file

Assuming you have the program loaded you can then just type in:

OPEN3,4:CMD3
LIST
CLOSE3

*Remember that Vice emulates the Commodore layouts, which means on the PET machines, they use a number pad.

The above commands will open up the printer, print the listing output to the printer, then close the printer device.  If all went well you’ll have the source dumped to viceprnt.out although PETSCII won’t render on ASCII systems, nor will the machine language portion, and a lot of the BASIC may get down shifted but you can always fix that with tr.

tr ‘[:lower:]’ ‘[:upper:]’ < c64_lemonaide.bas > c64_lemonaide_upper.bas

BASIC language subset/dialect in C++

Posted on by
4

This one came to me from Peter, a set of C++ macros and define sets that implement a subset of BASIC.

YES, that is correct, BASIC.  It even has line number!  Let’s look at a simple hello world!

type hello.bas
#include “ptsvubas.cc“

BEGINBASIC(int,main,(int argc, char* argv[]))
10 PRINT “Hello, world!”;
20 GOTO 40;
30 PRINT “I am not printed”;
40 END;
ENDBASIC

It’s compiled with GCC like this:

c++ -pipe -xc++ -fpermissive -w -o hello.exe hello.bas

And then run it!

Hello, world!

Neat!

From the docs in the main .cc file:

Implemented a BASIC language dialect/subset, with the following restrictions:

  •  All variables and statements must be allcaps
  • All lines must begin with a line number from 1 to 32767
  • All lines must have a trailing semicolon
  • One statement per line (except IF-THEN)
  • “THEN” must NOT be followed by a “GOTO” nor “GOSUB”!
    • Implemented keywords:
    • IF <C-style expression with “==” in case of equality> THEN <label>
    • GOTO <label>
    • GOSUB <label> / RETURN
    • STOP [optional errorlevel/return value]
    • END [optional errorlevel/return value]
    • LET <variable>=<expression>
    • PRINT <strings and/or variables in arbitrary order>
    • INPUT <one or more variables>
    • DIM <array variables with number of elements, p.ex. “NP(42)”>
    • FOR/NEXT loop (NEXT’s argument is mandatory, exactly one variable)
    • PRINT interprets comma as semicolon, except on the ENDS
      • thus PRINT does NOT interpret comma as tab injection
        basically, PRINT is some kind of writeln()
        but can be tricked: if CHR$(0) is inserted somewhere, it won’t print
        the remaining part including the trailing newline!
        variables are all float types, predeclared, and their names at most 2 chars long
    • (numerical) arrays can be used, must be declared before their first usage
    • Array numberings: DIM A(8) means that A(0) till A(7) are declared this way

So it’s not 100%, there is no strings, not even a REM (conver to C++ comments) so it’ll be a while until you can build more traditional basic programs.

Simple Mandelbrot set in BASIC

I used “mingw-i686-7.1.0-win32-dwarf-rt_v5-rev0” to test this on Windows.

You can download ptsvubas from it’s site here: vm01.unsoft.hu/~np/basic/latest/

Usborne collection of 1980’s computer books!

Posted on by
2

usborne

Back in the 1980’s home computers were a new and exciting thing, and with these machines came very technical manuals.  But us young children wanted to program, and thankfully companies like Usborne filled the gap by providing programming books geared towards kids!  It was a golden age as every machine had a basic interpreter.  Then for some reason software companies (Microsoft/IBM) didn’t think it was a good thing anymore bundling in languages with their OS’s, or worse thinking that development tools should be a source of revenue and pricing amateurs out of the market (seriously SCO, $5000 for a C compiler?)  But now thanks to the common carrier network we all have (the internet) the rise of open and free software hackers have taken things into their hands, and we are back to empowering users.

So I thought it was interesting that Usborne opened up a bunch of it’s older books.  All available in PDF, free for personal use.

First computer library

Introductions to programming

Games

Adventure games

You can see their page with full details here.

 

CBM Basic

Posted on by
8

I found this repository by accident, cbmbasic which is a ‘portable’ version of the old Microsoft Basic for the Commodore 8bit computers in C which can run on any manner of machine.

Really cool, right?

So for the heck of it, I fired up the x68000 toolchain, and in no time after gutting the file open operation as some stuff isn’t defined, and I wanted to see it run, I had a working executable.

C

CBM Basic

All the commands MUST BE IN UPPERCASE… Then again the Commodore did default to upper case, so I guess that isn’t a surprise.  There is no ‘system’ command to take you out of basic, but Control-C works just the same.

The other intersting thing, is that on the authors blog, pagetable.com, the original source code for the 6502 basic has been found.  Notably this version includes portions written by Bill Gates.  It is a very fascinating read.

50 years of BASIC!

Posted on by
3

Wow time flies!

So if you are interested, TIME magazine has a fantastic article on the history of basic!

To celebrate, there is the GE simulator ‘true basic‘ on Dartmouth , and another more obscure (and seemingly deleted) simulator for MS-DOS.  Which is interesting at least for more demo programs.

There is even a ‘web‘ based simulator, but I haven’t tried it.

For the heck of it, I took an old ‘game’ taxman.bas (Downloaded from here, and which I extracted with SIMH) and with a couple of line changes, got it to run.

10 DIM T(10)
20 DIM L(50)
101 PRINT
104 PRINT”HI, I’M THE TAXMAN”
106 PRINT”DO YOU WANT THE REGULATIONS”
108 LET R = 1
110 IF R<>0 THEN 900
120 REM ***INITIALZATION
122 GOSUB 800
124 REM ***THE HUMAN TAKES A NUMBER
126 GOSUB 500
128 REM *** COMPUTE THE HUMAN’S AND TAXMANS TOTLES
130 GOSUB 570
132 REM *** PRINT THE NEW LIST
134 GOSUB 600
136 REM *** CHECK IF ANY NUMBERS STILL HAVE FACTORS
138 GOSUB 650
140 IF M=1 THEN 126
142 REM *** FIND THE WINNER
144 GOSUB 700
146 REM *** AGAIN?
148 GOTO 750
496 REM
497 REM *** THE HUMAN MOVES
498 REM
500 PRINT
502 PRINT
504 PRINT”YOU TAKE”;
506 INPUT K
508 LET K=INT(K)
510 IF K <= 0 THEN 750
512 IF K <=N THEN 518
514 PRINT K;”IS NOT IN THE LIST — TRY AGAIN.”
516 GOTO 502
518 IF L(K)=0 THEN 514
520 REM FIND ALL THE FACTORS
522 IF K>1 THEN 530
524 PRINT”THERE ARE NO FACTORS OF”;K;”FOR ME.”
526 PRINT”ARE YOU TRYING TO SHORT-CHANGE THE TAXMAN?”
528 GOTO 502
530 LET M=0
532 FOR I=1 TO K/2
534 IF L(I)=0 THEN 544
536 IF K <> I*INT(K/I) THEN 544
538 LET M=M+1
540 LET T(M)=I
542 LET L(I)=0
544 NEXT I
546 REM CHECK WETHER THERE WERE ANY FACTORS
548 IF M=0 THEN 524
550 LET L(K)=0
552 RETURN
566 REM
567 REM *** COMPUTE THE HUMAN’S AND TAXMAN’S TOTALS
568 REM
570 LET Y=Y+K
572 PRINT”YOUR TOTAL IS”;Y
574 PRINT”I GET”;
576 FOR I=1 TO M
578 PRINT T(I);
580 LET Z=Z+T(I)
582 NEXT I
584 PRINT
586 PRINT”MY TOTAL IS”;Z
588 RETURN
596 REM
597 REM *** PRINT THE NEW LIST
598 REM
600 PRINT
602 PRINT”NEW LIST:”;
604 LET M=0
606 FOR I=1 TO N
608 IF L(I)=0 THEN 614
610 PRINT I;
612 LET M=1
614 NEXT I
616 RETURN
646 REM
647 REM *** CHECK IF ANY NUMBERS STILL HAVE FACTORS
648 REM
649 REM CHECK IF THE LIST IS EMPTY
650 IF M=0 THEN 690
652 FOR I=N TO 4 STEP -1
654 FOR J=2 TO I/2
656 IF L(J)=0 THEN 664
658 IF I<> J*INT(I/J) THEN 664
660 LET M=1
662 RETURN
664 NEXT J
666 NEXT I
668 REM THE TAXMAN GETS THE REST OF THE NUMBERS
670 PRINT
672 PRINT”I GET”;
674 FOR I=1 TO N
676 IF L(I)=0 THEN 682
678 PRINT I;
680 LET Z=Z+I
682 NEXT I
684 PRINT”BECAUSE NO FACTORS OF ANY NUMBER ARE LEFT.”
686 PRINT”MY TOTAL IS”;Z
688 LET M=0
690 RETURN
696 REM
697 REM *** FIND THE WINNER
698 REM
700 PRINT
702 IF Z>Y THEN 708
704 PRINT”YOU”;Y;” TAXMAN”;Z;” YOU WIN!!!”
706 RETURN
708 PRINT”TAXMAN”;Z;” YOU”;Y;” THE TAXMAN WINS.”
710 RETURN
746 REM
747 REM *** AGAIN?
748 REM
750 PRINT
752 PRINT
754 PRINT”AGAIN (Type 0 for NO)”;
756 INPUT R
759 IF R=0 THEN 999
760 GOTO 122
796 REM
797 REM *** INITIALATION
798 REM
800 PRINT
802 PRINT”HOW MANY NUMBERS DO YOU WANT IN THE LIST”;
804 INPUT N
806 LET N=INT(N)
808 IF N <= 0 THEN 999
810 IF N=50 THEN 818
811 IF N<50 THEN 818
812 PRINT”AT THIS TIME, REGULATIONS ALLOW A MAXIMUM OF 50 NUMBERS.”
814 GOTO 800
818 LET Y=0
820 LET Z=0
822 PRINT
824 PRINT”THE LIST IS:”;
826 FOR I=1 TO N
828 PRINT I;
830 LET L(I)=1
832 NEXT I
834 IF N>1 THEN 844
836 PRINT
838 PRINT”HOW VERY GENEROUS OF YOU TO FORFEIT ALL TO THE TAXMAN.”
840 PRINT”TAXMAN 1 YOU 0 THE TAXMAN WINS.”
842 GOTO 750
844 RETURN
896 REM
897 REM *** INSTRUCTIONS
898 REM
900 PRINT
901 PRINT”YOU TRY TO BEAT THE TAXMAN.”
902 PRINT
904 PRINT”WE START WITH A LIST OF WHOLE NUMBERS IN NUMERICAL”
906 PRINT”ORDER (YOU DECIDE HOW MANY).”
908 PRINT
910 PRINT”YOU TAKE A NUMBER FROM THE LIST — THE TAXMAN GETS”
912 PRINT”ALL THE FACTORS OF YOUR NUMBER THAT ARE STILL LEFT”
914 PRINT”YOUR NUMBER AND ALL OF ITS FACTORS ARE THEN DELETED”
916 PRINT”FROM THE LIST.”
918 PRINT
920 PRINT”FOR EXAMPLE, SUPPOSE YOU WANT TEN NUMBERS TO BE IN THE LIST.”
922 PRINT”THEN THE LIST WOULD BE: 1 2 3 4 5 6 7 8 9 10″
924 PRINT
926 PRINT”IF YOU TOOK 8, THE TAXMAN WOULD GET: 1, 2, AND 4″
928 PRINT”AND THE NEW LIST WOULD BE: 3 5 6 7 9 10″
929 PRINT”TYPE <RETURN> TO GO ON”
932 PRINT”THE TAXMAN MUST GET SOMTHING EVERY TIME SO YOU CAN”
934 PRINT”ONLY PICK A NUMBER THAT HAS FACTORS LEFT,”
936 PRINT
938 PRINT”WHEN NONE OF THE REMAINING FACTORS,”
940 PRINT”THE TAXMAN GETS THEM!!!”
942 PRINT
944 PRINT”YOUR SCORE IS THE SUM OF NUMBERS YOU TAKE.”
946 PRINT”IF YOU WANT TO GIVE UP, TAKE 0.”
948 PRINT”GOOD LUCK !!!”
950 GOTO 122
999 END

Taxman!

Taxman!

It’s not much to look at, but it is kinda neat to see it run.

But really, read the Time article!