From: K3H (ALBERT SCHOFIELD) Subject: TAPE TO DISC ON THE BBC B BUGEYES II is a particularly difficult game to transfer to disc as the last part has changing filenames and is also locked in a special way so that if it is unlocked and then relocked it will not work. Also it needs to be downloaded to &900. BUGEYES II is in five parts:- STARMAN, BUG1, SCREEN, BUG2 and changing filenames. The first part, STARMAN, is a basic program and has hidden lines. Load this in from tape and delete all lines from 41 upwards using DELETE41,1040. This will also delete the hidden lines. Add the following lines:- 50 *KEY0 *RUN BUG1|M*RUN BUGEYES|M 60 *FX138,0,128 70 END Save this to disc as STARMAN. The next two parts, BUG1 and SCREEN can be transferred to disc unaltered. The fourth part, BUG2, needs to have it's execution address altered so load it in using *LOAD""1900. Save it to disc using *SAVE BUG2 1900+356 709 400 To load in the last part an unlocking utility will have to be used. Also use *OPT2,0 to force the changing filenames to load. Load it in at &1900. Ignore the File? messages. Save it to disc using:- *SAVE BUGEYES 1900+4F00 1E0A 900 This file will have to be downloaded to &900 using the method of your choice. If you have the WATFORD DFS do not use *MRUN as this clears the screen. Switch the computer off then on again. Chaining STARMAN will now load and run the game. The top of the screen will be corrupted by the downloading but this does not interfere with the playing of the game. If you have sideways ram and you wish to have a perfect load then the last part BUGEYES, instead of adding a downloader, can be put into two rom images. It is too long to go into one. Save the rom images as BUG1R and BUG2R. Add the following lines to the first part, STARMAN, instead of as shown earlier:- 50 *KEY10 CLS|M*RUN BUG1|M *ROM|M *OPT1,2|M*RUN BUGEYES|M 60 ?&FF30=0:*LOAD BUG1R 8000 70 ?&FF31=0:*LOAD BUG2R 8000 80 CALL!-4 Chaining STARMAN will now load the rom images and run the game for a perfect load. To: 999 (all members) ReplyTo: D5B (Jon Ripley) From: K8G (Jonathan Harston) Subject: Reading DOS disks There are a variety of methods for getting BBC data into a PC. As well as BBC disk readers for the PC as Jon mentioned last month, there are various DOS disk readers for the BBC. Of these, I know about: Petrov DOS FS: A DOS filing system for Master or B+. Allows full filing-system access to DOS disks. There are some unimplemented features, notably there is no *RENAME command, but it is fully usable. It has to run in sideways ram. DOSUtils, DOSCopy, DOS-BBC Programs that allow you to transfer files between types of disks. To access any DOS disks you need the 1770 controller as the 8271 in the BBC B can only do single density. You can access disks up to 720k in size. The 1770 cannot access 1.2M or 1.44M disks (the ones with two holes in them) The programs are useful for transferring between disks. If DOS-FS was more fully implemented it would be the better method. At some point I intend to implement DOS FS as part of HADFS, but things seem to be plodding a bit just now. All the above programs are available from JGH PD on disk ??. Petrov DOS-FS was on 8-Bit issue disk 51. To: 999 (all members) ReplyTo: D6E (Richard Harker) From: K8G (Jonathan Harston) Subject: Keyboard DIP switches The bank of eight DIP switches at the bottom of the keyboard define various start-up options. Numbering from left to right, they are: 1: DNFS filing system priority, DISK or NET takes precedence. 2: The only thing I know that uses this bit is HADFS. It sets whether to use floppy driver or external driver for drive 1. 3: 4: Disk speed, similar to FDRIVE configuration setting on Masters: sw3 sw4 step settle load 1 1 4ms 16ms 0ms 1 0 6ms 16ms 0ms 0 1 6ms 50ms 32ms 0 0 24ms 20ms 64ms You can try selecting the fastest speed your drives will operate at to speed up disk access. Most modern drives will happily go at setting 3. 5: Reverses action of Shift-Break and Break. 6: 7: 8: Startup mode. The link setting are copied to Osbyte 255 on Ctrl-Break, so to see what the effects would be without setting the switches, use *FX255,newvalue where newvalue is made up from the bits listed above, in the reverse order, ie switch 1 -> bit 7; switch 8 -> bit 0. To: 999 (all members) ReplyTo: D6E (Richard Harker) From: K8G (Jonathan Harston) Subject: Socket on keyboard The socket to the left of the keyboard is for inserting serial PHrase ROMs, or PHROMs for use with the speech system. Most people who do use the 'ashtray' as the hole was known usually put an external sideways Rom socket there instead. To: 999 (all members) ReplyTo: D6E (Richard Harker) From: K8G (Jonathan Harston) Subject: ULA Heat Sink Why is the heat sink there? ... To get rid of the heat of course. This question makes no sense. To: 999 (all members) ReplyTo: 0E7 (F.W.Nevin) From: K8G (Jonathan Harston) Subject: Fate of 3.5" disks How can CD-Roms replace 3.5" floppies? CD-ROMs are a read-only media. There will always be a need for a writable storage medium on which you can carry information from one machine to another. What do you mean by a 3.5" DD PSU? Do you mean a disk drive PSU... in which case most electroncs dealers will be able to comply. Or do you mean a 3.5" DD disk drive. In which case, again, most electroncs dealers will be able to comply. Internal (ie powered by the computer) 3.5" disk drives currently cost around £30. (<- look! a pound sign!) To: 999 (all members) ReplyTo: D9F (Gary Scott) From: K8G (Jonathan Harston) Subject: 3.5" disk drive A switchable 3.5" disk drive? Why? All 3.5" disks are 80-track, so what point would there be in switching the drive to 40 track? Do you need anything other than the disk drive and ADFS to use it? Well, you need the 1770 controller inside your machine. ADFS will not access floppies without that, but I seem to remember from earlier messages that you do have the 1770. Hmm... a connecting lead... A spare power socket... About sixty square inches of space on the desk at the side of the computer... To: 999 (all members) ReplyTo: D6K (Mike Mallett) From: K8G (Jonathan Harston) Subject: CP/M and hard drives Back in issue 51 you had a message asking how to use a hard drive with CP/M. I wrote a reply, but it seems to have got lost. Anyway... The BIOS (Basic Input/Output System) supplied with the Acorn Z80 only provides access to two drives, floppy 0 and 1. The simplest way to provide dard disk support is to patch the BIOS to make it access a file on the hard drive whenever drive, eg C: was accessed. I'm working on this just now, and I'll send you a copy as soon as it's ready. A better method would be to allow full access to the BBS file structure from CP/M. This is a bigger job, as it requires rewriting the BDOS, not just patching the BIOS. I've been planning to get around to doing this for some time. To: 999 (all members) From: D6G (SPROW) Subject: Inside out Last month Richard Harker was puzzled about the machine he has: 1)SWITCHES ON THE BOTTOM OF THE KEYBOARD PCB These are option links (replaced on the Master by the *config. options stored in battery backed RAM) that allow configuration of the machine on power up.They are not normally fitted to the PCB,to save money,but may be fitted (Maplin order code XX27E) very easily.You just happen to have a board that has them already added. 2)THE ASHTRAY On a BBC B the brown keyboard overlay has a punch out hole on the LHS,this was intended to be removed when the speech system was added.Unfortunately Acorn were a bit late in releasing this and not many people bought it when they did - you have a machine which has had it fitted at one ppint. The 20 way edge connector was for games cartridges which were considered as additional PHROMs to the speech system.They would load as fast as disks,but I've never come accross any to try. 3)IC 61-68 Using the BBCISS7 program from my homepage,this reveals that they are indeed RAM,perhaps yours was a model A in a previous life.I'd not recommend unplugging them. 4)THE HEATSINK On the right inside is on the Ferranti ULA (used as part of the video system) which was rather poorly designed and overheated.Acorn redesigned it later and you don't need a heatsink on those. 5)AB ELECTRONICS They built the BBC in Wales. So there we go. To: 999 (all members) From: D6G (SPROW) Subject: Composite video Last issue,I was asked how to make the colour modifications to BBC's for the composite video. I explained that Acorn left it B&W as they expected the RGB system to be used more,and that having colour composite video does in fact degrade the quality of the RGB side. I have now found,after much trawling the details of how to modify ALL board issues: On Issue 1 ,2 & 3 board a 470 picaFarad capacitor should be fitted between the emitter of Q9 (identified by an "e" next to one leg) and the base of Q7 (the central Leg). On Issue 4 and later, the capacitor is on-board and can be connected simply by fitting link 39 which may be found next to the modulator in the far right hand corner of the PCB. On the BBC Model B+ link S26 should be made. On Master 128 issue 1 boards a 470 PicaFarad capacitor should be connected between the East Leg of R137 and the East Leg of R153 which are located directly to the East of the modulator. Connections should be made on the component side of the PCB with the leads of the 470 PicaFarad capacitor being soldered directly to the leads of the two resistors. On Master 128 issue 2 boards link LK11 should be made. There,I think that covers just about every machine type! Best of luck, Robert Sprowson. To: 999 (all members) From: D6G (SPROW) Subject: Doomsday The number of people fretting about the year 2000 causing problems with the Master 128 has been increasing. All of the disk user groups,such as EUG and 8BS have had articles,but I can assure you not to worry. I have produced a ROM that will correct the problem & also extend the century range available to Jan 1st year 1800 until Dec 31st 2199. These can now be ordered for my usual ROM prices,`4,including instructions. The program comes on an 8k ROM,and uses Acorn calls only.If you're not using a Master,but do have a real time clock,check in your manual before ordering that it supports OSword 14 and 15 and OSbytes 161 and 162.There is also a program on this disk to detect whether these calls are supported which you should try before ordering. Not only does it include the date fixer but also a *DRIVE to *DIR: converter to help ADFS run programs written with DFS in mind (this patch is also available from my web page). As a bonus there's a current working directory command,which shows the CWD if you use *DIR with the drive parameter missing.This is also on my web page,along with many other titles. If you're not using a Master,you'll find the built in *ROMS command and *SHOW command very handy. To improve reverse compatability from Master to BBC the *CLOSE command has also been included. An additional *CONFIGURE command sets the current timezone,which can be used to toggle between BST and GMT. Please note that this should NOT be run from sideways RAM. Please state when ordering: 1)Your name 2)The return address 3)Whether you are using a Master/other All in all this looks to be a very handy ROM - after all time is literally ticking away... Web page: www.york.ac.uk/~rps102/bbc/bbc.htm Write to R.P.Sprowson 6 Bollinbrook road, MACCLESFIELD, Cheshire. SK10 3DJ.
Fax (01625) 431067
To: 999 and D6B (Richard Harker) From: D5B (Jon Ripley) Subject: Help Offered For Issue 4 BBCs For ease of answering I have reproduced Richard's questions here... 1) On the keyboard, in the bottom right corner a bank of 8 dip switches has been added. What are they for? These DIP switch settings reflect the default setting of start up options as set by OSBYTE 255. (*FX 255) There is a space on the bottom right of most BBC keyboards where a bank of switches can be added if not already present. These switches allow a small degree of system configuration. Each of the eight switches corresponds to a bit of the data. Bit 7 on the leftmost switch to bit 0 on the right. Switch on for 1 or off for 0. The format is as follows... Bits 0-2 Screen mode (000=0 to 111=7) 3 = 0 to !Boot on Shift-Break = 1 to !Boot on Break 4-5 Set disc speed = 00 for fastest through to 11 for slowest 6 Reserved 7 = 0 DNFS starts in DFS = 1 DNFS starts in DFS Where the switches are not present they are read as being switched off. On the Master and Compact, only bit 3 has any effect, the others being ignored. There are no equivalent switchsettings on the Electron. 2) On the keyboard, in the middle left, a blue socket has been added. It is hard to describe. It has 2 rows of 10 pins, and then further, on the same piece of plastic, 2 rows of 2 pins. What are these for? I am not sure what these switches are for but I remember something about a bank of 8 switches (or links) which set the ECONET station number of the machine (also appears at &FE18 in the memory map). 3) On the keyboard, at the top left, about 4cm from the connector to the main computer, there is a row of of 10 pins. These are connected to the socket as described above. Does this connect to PL14 on the mother board. What does it do. This applies only to the BBC B and B+. Where no pins are present it is possible to solder a row of pins to the keyboard. It connects to the row of pins directly beneath it. This connection is used when a speech upgrade is fitted to the BBC to relay infomation. 4) ICs 61-68 on the motherboard are socketed. If I am right in thinking that these are memory chips, would removing them make my computer 16k? Not having a BBC to hand I can't help with this one at the moment. 5) A number of other chips on the board are socketed (eg the SA5050) was this common practice on the earlier issues BBCs. I am not entirely sure of the reasoning behind socketing some of the roms on some motherboards whilst soldering on others but generally there is more of it on earlier BBCs. To: 999 (all members) From: D5B (Jon Ripley) Subject: Tape to disc on the BBC B Many thanks to Albert Schofield for his series on transferring tape games to disc. Transferring old BBC tapes games to disc can be quite a daunting task for many users even with games that have no protection at all. Duplicating taped games nowadays is quite a simple task, all that is required is a simple hi-fi system. Games producers began to use quite sophisticated protection techniques to stop hackers examining the inner workings of their games. The operating system allows tape files to be locked and provides a method that most modest users will be unable to bypass. Efforts to deter the more sophisticatedhackers included using a different way of saving the files to tape so only their own tape loaders would work. A good example of this is the Psycastria game, listening to your tape of this game you will notice it sounds totally different to the average tape game. But back to discs... More next time!