Integra-B OS (IBOS)

Table of contents

• Overview
• Building
• Getting help
• Changelog

Overview

This repository holds source code for the IBOS ROM used with the Integra-B expansion for the BBC Micro. It is based on a disassembly of the last official release by Computech (1.20) and can rebuild that version as well as newer versions containing bug fixes and enhancements.

Building

You will need a copy of beebasm 1.09 or later in order to build the sources. Each version has a separate top level file, e.g. IBOS-120.asm for v1.20. To build any particular version, execute beebasm using a command like:

beebasm -w -i IBOS-120.asm

This will create an IBOS-120.rom file, which is the IBOS ROM image. The -w option is important as the source code uses macro names which start with 6502 mnemonics and these will not assemble correctly otherwise.

All the top level files simply define some constants and include the main source file IBOS.asm.

There is a Makefile which will build all the versions and verify their md5sums to check they have built correctly. It will also create tags files suitable for use with vim or emacs to help with navigating the source.

Getting help

If you have problems or suggestions for improvement, please post in the IBOS thread on the stardot forums. This is preferred to raising issues in github, but if you want to browse or submit a github issue, please make sure you are using the main repo here.

Changelog

• v1.20 (1989):

  • Last official release by Computech.

• v1.20-em:

  • This is a patched version of v1.20 distributed with the b-em and BeebEm BBC Micro emulators. It identifies itself as v1.20 so can only be distinguished by its filename within the emulator installation (integra12p.rom in b-em, IBOS12P.ROM in BeebEm), examining the ROM or checking for the following changes.
  • Set current date to Saturday 1st January 2000 on full reset; previously the date was set to Monday 1st January 1900.
  • Set configured FDRIVE to 0 on full reset; previously this was set to 3.
  • On full reset, set DFS as the default filing system when DNFS is the configured default filing system ROM; previously this was set to NFS.

• v1.21 (2019):

  • (These changes are described as if v1.20-em is the previous version.)
  • Copyright string and startup banner text changed from "Computech" to "BBC Micro"
  • Set configured LANG to &E and FILE to &C on full reset; previously these were both defaulted to the bank containing IBOS (typically &F).
  • Set configured TV to 255,0 on full reset; previously this was set to 0,1.

• v1.22 (2021):

  • Fix lock up with ANFS 4.18. This was a result of ANFS 4.18 re-issuing service call 1 during reset, which caused IBOS to claim vectors twice and end up in an infinite loop as a result.

• v1.23 (April 2022):

  • Make IBOS's REMV handler return the character in both A and Y when operating on the printer buffer whether the caller is trying to examine or remove characters. This fixes problems when printing to a network printer. Earlier versions returned the character in Y for examine calls and in A for remove calls, which is the wrong way round but conveniently works correctly most of the time due to quirks in OS 1.20. Returning the character in both registers all the time is safe and maximally compatible.

• v1.24 (August 2022):

  • Set configured LANG and FILE to the bank containing IBOS (typically &F) on full reset, reverting the change in v1.21.
  • Apply the configured PRINTER option later during the reset (break) sequence; this fixes problems when the configured PRINTER option is a network printer.

• v1.25 (November 2022):

  • Include the command argument specification in the error message generated when a * command's arguments are incorrect. Earlier versions behaved inconsistently and sometimes did this and sometimes didn't.
  • Don't beep when parsing an integer from the command line fails.

• v1.26 (November 2022):

  • Support OSWORD &0F (write real time clock).
  • Accept spaces as well as slashes to separate date components in *DATE= arguments.
  • Accept three letter English month abbreviations as well as numeric months in *DATE= arguments.
  • Set configured TV to 0,1 on full reset, reverting the change in v1.21.
  • Allow *CONFIGURE LANG to optionally take two ROM banks, the first being the ROM bank to enter as a language when no tube is active, the second being the ROM bank to enter as a language when the tube is active. If a single argument is specified, this is used regardless of tube presence or absence, as before.
  • When no tube is active, check before entering the CONFIGURE-d language that it is not a HI language (i.e. its relocation address, if any, is &8000) and enter the IBOS No Language Environment instead if it is. This avoids hanging if (for example) the CONFIGURE-d language is HIBASIC and there is no second processor.
  • Re-arrange battery-backed RAM storage of CONFIGURE FILE and CONFIGURE LANG to accommodate having two separate languages configured for tube/non-tube, as described above. This will mean users need to issue CONFIGURE FILE and CONFIGURE LANG commands after upgrading, and CSAVE-d configurations from earlier IBOS versions will be incompatible with IBOS 1.26 and newer. A valid language (probably the IBOS No Language Environment, which allows commands to be entered) should still be entered after upgrading without the need for a full reset.
  • Default LANG (both tube and non-tube) and FILE to &F on full reset. This will typically be the bank containing IBOS, but the other changes in this version mean that even if it isn't, a language will still be entered successfully.

• v1.27 (August / September 2024):

  • New release primarily to support for additional features of the V2 hardware, including extra RAM & emulated PALPROMs in banks 8..11. Various bug fixes and enhancements to improve user experience on both V1 & V2 hardware.
  • Implement new software Write Protect & Write Enable commands, SRWP & SRWE. These commands will only function on V2 hardware. They will generate a 'V2 Only' error if you attempt to run them on V1 hardware
  • SRWP & SRWE have 'T'emporary option whereby the W/E and W/P actions will only apply until reset is carried out, or the command is run again (on any bank) without the T option.
  • Don't re-enter the current language on TUBE OFF if it is a HI language. In this case we behave as on a CTRL-BREAK and enter the language specified by CONFIGURE LANG, falling back to the IBOS NLE if that isn't usable.
  • Add new column to *ROMS output. This column will display 'r' if bank is set to use internal RAM, 'R' if the external ROM socket is being used, or '2', '4' or '8' if a PALPROM has been loaded. The numeric value represents the total number of 16K chunks used by the PALPROM.
  • If a bank is UNPLUGged, the ROMS output will now show the 'U'nplugged status even if the bank is empty. Applies to both V1 and V2 hardware.
  • Update RAM calculation for startup banner.
  • Can now calculate total RAM above 256K.
  • Will now display a maximum of 320K for V1 hardware, using two private RAM registers to store RAM presence of all 16 banks in 16K blocks. These registers can be set by FX162,126,x (bit 0=bank 0, bit 7=bank 7) and FX162,127,y (bit 0=bank 8, bit 7=bank 15), although it may be simpler to use an updated version of the RAMSET utility to do this. RAM presence was previously implemented using a single register to manage all 16 banks in 32K blocks so will need manual fixing after upgrading from an earlier version, although this is entirely cosmetic and won't cause anything to break if it isn't done. This also means *CSAVE-d configurations will not be compatible with earlier IBOS versions and vice-versa.
  • Will display a maximum of 512K for V2 hardware. Without PALPROMs enabled, the maximum RAM will be 320K, and will be influenced by the position of the ROM / RAM jumpers on the IntegraB board.
  • On V2 hardware, if PALPROMs are detected in banks 8..11, this will influence the calculation based on the size of PALPROM in use, increasing the usage up to a maximum total of 512K.
  • Update SRLOAD, SRWRITE, SRWIPE, SRROM & *SRDATA commands to be PALPROM aware. These commands will reset a PALPROM bank back to a standard 16K RAM bank to prevent PALPROM switching on a non PALPROM ROM image.
  • Update SRWIPE / SRDATA / *SRROM commands to test if all banks in list can be written to. Will abort without making any changes and report a 'Not W/E RAM' error if any bank in list can't be written to.
  • Update SRLOAD & SRWRITE commands to test bank can be written to. Will report a 'Not W/E RAM' error if the bank can't be written to.
  • Update SRDATA / SRROM commands to test for free banks. Will abort without making any changes, and generate a 'RAM occupied' error if any bank in the list is already in use.
  • Update SRLOAD / SRWRITE commands with 'T' option that will 'T'emporarily Write Enable the bank during the SRLOAD / SRWRITE operation. This avoids the need to do a separate *SRWE (T) beforehand. Works only on V2 hardware, will be silently ignored on V1 hardware.
  • Update SRLOAD command with 'P' option that will Write Protect a previously Write Enabled bank following completion of the SRLOAD operation. This avoids the need to do a separate *SRWP afterwards. Works only on V2 hardware, will be silently ignored on V1 hardware.
  • Reset PALPROM config parameters during Integra Reset if PALPROM bank is Write Enabled at the point of reset.
  • Fix long-standing bug where SRLOAD & SRWRITE were not SRDATA ('RAM') aware. These commands will now reduce the SRDATA RAM counter if the bank had previously been configured as a SRDATA ('RAM') bank.
  • Preserve A in OSBYTE &6F (111), as all OSBYTE calls should.
  • Increase the buffer start address from PAGE to PAGE + &100, to avoid 'Bad Program' message using Q option to SRLOAD or SRSAVE ROM images when no BASIC program exists in memory.