~/.dosbox/dosbox-*.conf
;-------- bottom part
[autoexec]
# Lines in this section will be run at startup.
# You can put your MOUNT lines here.
mount c: /home/myusername/projects/dos
c:
The files
A.BAT – Runs editor, masm,linker (start with a<space>progname
DEBUG.COM – msdos debugger
EXE2BIN.EXE – exe to com (if segments allow)
GFX.ASM – example template (see below)
LINK.EXE – masm linker
MASM.EXE – masm compiler
Q* – editor stuff
Q.EXE – editor
SR.EXE – sourcer
SYMDEB.EXE
TASM.EXE – turbo assembler
TD.EXE – turbo debugger
TLINK.EXE – turbo linker
Template
; everything in 64k CS, DS, and SS are the same
.model small
; start pointer
.stack 100h
.code
start:
; set mode 13 (320x200 * 265 colors palette)
mov ah,0
mov al,13h
int 10h
; set pixel in the middle color 2 (cyan)
mov ah,0ch
mov al,2
mov cx,160
mov dx,100
int 10h
; wait key input
mov ah,0
int 16h
; set mode back to text
mov ah,0
mov al,3
int 10h
; exit to dos
mov ax,4c00h
int 21h
end start
Usage
start dosbox a gfx (edit gfx.asm example) esc, q, e gfx (run program)
I mentioned a 2 ROM setup because the 8086 is 16bits instead of 8. So I was wondering that maybe a recompile was needed, or the data being split over two roms (odd/even)
The guy from GLABios was so kind to build me two interleaved roms.
So while working on a padded bench, I tested the ROMs.
Working outside .. on the padded bench
Back to the roms, it didn’t work!
But I missed a detail in the technical manual (the bold text)
In Turbo XT /2 and Turbo XT /3, there are two 28-pin sockets for ROM, both of them are occupied by 2764 which stored the BIOS. The contents of the two 2764 are identical. One of them contribute the ODD Byte to the system and the other EVEN Byte. Together they support 16 Bit BIOS access.
I don’t know why this is how it works, but when I flashed two the same 28C64’s it worked! (I also tought that is was strange that both original roms had the same markings.
New romsGlabios shows 8088Real 8086
It workes!
Only remarks/observations:
There was a longer wait time before the CF Card was detected/accessed
GLABios mentions 8088 in the splashscreen, but the machine is a 8086
UPDATE
GLABios was not updated for displaying 8086 yet. Error 1701 was the (old spinning) harddisk not being connected.
Nice .. harddisk infomation like size, rom address and CHS
Today I was working on my own brew ISA card (wirewrapping). Did some mini modeling stuff. Sorted some pipetunes. And played around with my 8086.
Got it on a desk now, and replaced the harddisk with the CF card. Also got an old SoundBlaster working, so i wanted to see what of my old code could still run. Apparanty most code was compiled for 386/486 🙁 So i recompiled some stuff. Below a horizontal scroller example.
Meanwhile i got my new fans in for my NUC (Kodi player, it was making a hell of a noise due to bad ball bearings.
Adding a picture: Most used is loading a koala picture. Never done it like this before, luckily loads of retro lovers are posting code examples. There are a lot of tools now available on PC. (Windows and Linux)
Acme : compiler i’ve used for this example Retropixels : converting jpg into koala Exomizer : packing/compressing the C64 prg (16k to 5.4k) Sidreloc : relocator for SID files.
Exomizer command with effect: (NOTE on linux you have to use single qoutes!)
retropixels -r 64 --format prg bottom.jpg ; for a prg (not used)
retropixels bottom.jpg ; for a koala picture
exomizer sfx 0x080d bottom.prg -x 'lda $fb eor #$01 sta $fb beq skip dec $d020 inc $d020 skip:'
# 0x080d is the starting address
Code
!to "bottomsm.prg",cbm
; start prg
* = $0801
; header for sys auto start
!byte $0b, $08, $00, $00, $9e, $32, $30, $36, $31, $00, $00, $00
PICTURE = $2000
BITMAP = PICTURE
VIDEO = PICTURE+$1f40
COLOR = PICTURE+$2328
BACKGROUND = PICTURE+$2710
* = $080d
sei
lda #<irq
ldx #>irq
sta $314
stx $315
lda #$1b
ldx #$00
ldy #$7f
sta $d011
stx $d012
sty $dc0d
lda #$01
sta $d01a
sta $d019 ; ACK any raster IRQs
lda #$00
jsr $1000 ; Call music
lda #$00
sta $d020 ; Border Color
lda BACKGROUND
sta $d021 ; Screen Color
; Transfer Video and Color
ldx #$00
.LOOP
; Transfers video data
lda VIDEO,x
sta $0400,x
lda VIDEO+$100,x
sta $0500,x
lda VIDEO+$200,x
sta $0600,x
lda VIDEO+$2e8,x
sta $06e8,x
; Transfers color data
lda COLOR,x
sta $d800,x
lda COLOR+$100,x
sta $d900,x
lda COLOR+$200,x
sta $da00,x
lda COLOR+$2e8,x
sta $dae8,x
inx
bne .LOOP
; Bitmap Mode On
lda #$3b
sta $d011
; MultiColor On
lda #$d8
sta $d016
; When bitmap adress is $2000 ; Screen at $0400 ; Value of $d018 is $18
lda #$18
sta $d018
cli
.MYLOOP
jmp .MYLOOP
irq
lda #$01
sta $d019 ; ACK any raster IRQs
jsr $1003 ;Play the music
jmp $ea31
; Data parts with headers cut
* = $1000
!binary "bottom1000.sid" ,, $7c+2
* = PICTURE
!binary "bottom.kla",,2
I really like GlaBios for my 8088, so today I got my Laser XT/3 8086 machine from the attic.
Mmm TWO ROM’s thats interesting
Looking futher in the schematics I found this. Apparantly there is a 8K ROM configured in a D0-D7 + D8-D15 setup. (16 bits)
Found a technical manual, this is a excerpt.
In Turbo XT, there are two 28-pin sockets for ROM, one of them is occupied by a 2764 which stored the BIOS (Basic Input Output System). The other empty socket is used to house a 32K ROM, such as the BASIC ROM
And about the XT/3 version which I have.
In Turbo XT /2 and Turbo XT /3, there are two 28-pin sockets for ROM, both of them are occupied by 2764 which stored the BIOS. The contents of the two 2764 are identical. One of them contribute the ODD Byte to the system and the other EVEN Byte. Together they support 16 Bit BIOS access.
This could be an interesting chat with Greg ..
Meanwhile i’m going to look how to split a rom into odd/even. Maybe i have to write a little python program for this.
Well, thats enough for today.
Lets fix my Cat S60 Flir phone, so i can track the hedgehog in our garden. (Battery replacement and powerbutton fix)
Hard to remove backcover and a sh*tload of screwsAt least the battery replacement was a breeze
I fixed several phones before, (broken screen. touch not working). But I hate how some manufacturers build them.
It’s fitted with a 64Mb card. Note: the XT at my parents place had a 20Mb harddisk!
It can boot / emulate a harddisk with MsDos installed.
Replace an old or dead hard drive in a vintage PC with a hassle-free, reliable CompactFlash card! Plug-in and go! (well, as much as you can expect with these old machines)
Brand new! Built and tested.
Open Source!
This bootable expansion card provides a Compact Flash card interface to 8-bit ISA systems such as PC/XT. Typically paired with a 64MB or 1GB CF card. Silent, and more reliable than an old mechanical hard drive.
By default the XT-IDE BIOS comes configured for: XT(and higher)-compatible BIOS. Use the XT-CF-Mini’s IDE interface at 300h, no IRQ. Boot first hard drive unless user presses A for floppy. Any of the above can be changed with the simple DOS utility and built-in switches.
Switches and jumpers control: I/O port for the 8-bit IDE (CF) interface I/O port for the Option ROM Option ROM Enable Option ROM Write-protect
Note: Not all CF cards will work. Most work, but some don’t adhere to the CF standard fully, and won’t work. The full size XT-IDE card with an IDE>CF adapter, is compatible with more CF cards.
https://github.com/Bluelavasystems/XT-IDE-CF-MINI XT-CF-Mini Pcb designed by Monotech Pc’s and released opensource GNU General Public License v3.0
It is from Blue Lava Systems, who took the schematics from Sergey Kiselev, who took the design from James Pearce.
The harddisk extension is XT-IDE Universal BIOS. And can be flashed.
ROM address D0000, and IO port 300h does not need a IRQ
After installing this on my 8088/v20 motherboard I tested this with GlaBIOS, but it gave me one beep, and after that it woukd reset the machine.
Testing with the original Phoenix Bios and PCXtBios worked for me.
UPDATE: Bad contacts and a eeprom I didn’t trust. Greg gave me version 0.2.5 of Glabios, which I burned to a new eeprom. And I cleaned some contacts. (Checksum rom changed with every reset)
The Card and my extension bios both run with all bios-ses
While doing some wood work, routing and painting. I managed to have some time to experiment with my PC200.
The Amstrad PC20 / Sinclair PC200 was a home computer created by Amstrad in late 1988. The machine was available in two versions, Sinclair PC200 and Amstrad PC20. (US/UK?)
The limited CGA graphical capabilities and PC speaker sound output were greatly inferior compared to other home computers of the time. I has a modulator to connect a TV and could do hercules graphics on a sub-9 interface.
I got this computer a long time ago. (I still have to post pictures of my collection and getting them out of storage)
Info about this machine:
Build in 1988, Intel 8086 @ 8Mhz 512KB memory 3.5″ Floppy drive TV Modulator Pal 640×200 CGA and Hercules
PC200
It still had a floppy in its drive, NIMMO Disk Juli 1992
Apparently this machine was used with a modem to do some interviewing for the University Amsterdam using Telepanel/Interview!
The ROM has several language options which you could set with dipswitches.
Debug part of ROM
Besides the machine having a “amiga” like case, it has two ISA slots behind a little trapdoor! How cool is that!
Dirty view of the ISA slots (One containing a RTC card)
Enabling only CGA on the machine and plugging in a Hercules card, you can do Multiscreen! CGA and MDA addresses don’t conflict! And if the ROM supports it .. dual screens baby!
Left Hercules and Right CGA
I used a debug command to fill the right screen
f b800:0 1000 ‘f a s h’
Cool little machine
Running old masm/precompiled machine code crashes. I’ll have to look into that.
I found some parts of our (Edk and Me) bootloader demo.
It was compiled using masm or tasm. Encountering a problem converting the code into a raw bin, to put on a floppy I diverted to another setup to try to get things working.
Using old code (below) and a example from YT, I made the following setup.
Visual studio code, with the x64 assembly plugin. xxd as hexviewer. fasm as assembler (This makes things easier, because it is a native Linux x86 compiler. So no need for dosbox anymore.)
;-------- snip
Start:
JMP SHORT BootHere
NOP
DB "FASH-EDK"
DW 512
DB 2
DW 1
DB 2
DW 0070h
DW 02d0h ;max. aantal sectoren van volume A
DB 0Fdh ;media descriptor
DW 0002h ;aantal sectoren per FAT
DW 0009h ;aantal sectoren per spoor
DW 2
DW 0
BootHere:
mov bp,5
tryboot:
push bp
mov bx,4000h
mov es,bx
mov bx,0
mov cx,2 ;vanaf sector 2
mov dx,0 ;drive A, kant 0
mov ah,02h
MOV AL,8
int 13h ;sector(en) lezen
pop bp
jnc bootok
dec bp
jnz tryboot
bootok:
mov bp,5
;---------- snap
New setup using fasm (bootloader) boot.asm
org 0x7c00 ; still not sure about this, have not found this in our demo
mov bx, 0x1000 ; load sector address
mov es, bx
mov bx, 0x0
; Sector read function
mov dh, 0x0 ; head 0
mov dl, 0x0 ; drive 0
mov ch, 0x0 ; cylinder 0
mov cl, 0x02 ; start sector
readdisk:
mov ah, 0x02 ; read sec
mov al, 0x02 ; demo is > 512 so 2 sectors
int 0x13 ; call bios
mov ax, 0x1000
mov ds, ax
mov es, ax
jmpcode:
jmp 0x1000:0x0 ; far jmp demo
; Expand bin to 512 byte sector
times 510-($-$$) db 0
dw 0xaa55 ; Sector header (ROM as this at the start)
Graphics demo i wrote a long time ago, converted into fasm loadpart.asm
mov ah,0
mov ax, 4f02h ; Set VESA video mode
mov bx, 10dh ; Your video mode number
int 10h
mov al,0
drawall:
mov dx,0
mov cx,0
drawloop:
mov ah,0ch
mov bh,0
push ax
int 10h
pop ax
inc al
inc cx
cmp cx,319
jc drawloop
mov cx,0
inc dx
cmp dx,199
jmp drawloop
jmp drawall
; complete sector with zeros
times 512-($-$$) db 0
Booting the demo in milli seconds using qemu. Next to do: Write this to floppy and test on real hardware.
A reset starts the virtual machine and boots from a virtual floppy. The drawing of the pixels is slow, because I used a int 10h function for every pixel, instead of writing to screen memory directly.
Got a part working again in PCem. This is from our bootdemo. A scroller and sector loader in a bootsector. Needed some include files masm, link, exe2com creates a 12- sector sized floppy. And we’ve got a (little distorted but working) Scroller in boot sector with custom font!
font: db 64 dup (0) ;space
db 0,0,2,2,0,0,0,0 ;!
db 0,2,2,2,2,0,0,0
db 0,2,2,2,2,0,0,0
db 0,2,2,2,2,0,0,0
db 0,0,2,2,0,0,0,0
db 0,0,2,2,0,0,0,0
db 0,0,0,0,0,0,0,0
db 0,0,2,2,0,0,0,0
"If something is worth doing, it's worth overdoing."
