8-bit Software Disc Magazine (c) Duncan Webster 1991
Issue 13 June 1991
SWR / Watford Solderless / Mixmania Discs
Most members will recall Andy Snodgrass' plea for help as none of the
Yorkshire Boys' excellent mixmania discs appears to work with his
Watford Electronics Solderless SWR board. As usual, the gauntlet was
immeadiatley taken up by an 8BS member, and here is Matthew Cocker's
informative and detailed reply to the problem. I will let him carry
on ...
----------------------------------------------------------------------
From: 8CT, Matthew J Cocker
To: YJ2, Andrew Snodgrass and Everybody Else Who Has MIXMANIA Discs.
Regarding:- Watford Solderless SWR problem and MIXMANIA II vol I and
II shortened versions for NON-SWR BBC's.
This article is NOT only for for people with SWR who are having
problems but is also for people with no SWR as they can use both
MIXMANIA II discs as they contain shortened versions of ALL Mixes but
the programs may nead modifying, there is a section below that
explains how to do this. I can supply modified versions of the
MIXMANIAs to suit your SWR and can also supply the two MIXMANIA II
discs modified to play the shortened mixes on NON-SWR BBC's, details
of this are listed below and the address is at the end of this
article.
This article explains why MIXMANIA discs don't always work correct
with certain SWR boards and explains how it may be made to work. It
also explains how people without SWR who have MIXMANIA II vol. I or II
can use the shortened versions of the Mixes. The problem is in the way
it scans the ROM and SWR banks as it won't usualy work properly and
tries to load the SWR version into an empty socket or into a socket
that doesn't exist if you don't have a 16 ROM Expansion Board.
The symptons that Andrew mentioned are similar to the problems I
encountered when I tried out MIXMANIA discs as my SWR is in a Watford
Solderless 16 ROM/RAM expansion board.
One thing that Andrew said was that he had two 32K CMOS RAM chips in
14L and 14H, I think they are infact only 8K each as the SWR only
usualy totals 16K per bank. The other thing I noticed was Andrew said
the Starwars animation worked with his SWR but I had my SWR READ and
WRITE protected when I first run that set of programs and it worked
fine so I don't think SWR is required to run the animations.
Right, back to the subject of MIXMANIA and SWR, I have checked out the
loader programs on the MIXMANIA discs and found out where it searches
for a SWR bank to load into, what it appears to be doing is just
looking for an empty socket as when I first ran 19MIX it tried to use
bank 4 but my SWR is in bank 14 like Andrews is. I put a ROM into
socket 4 and reran the program, it then tried to use bank 7 which is
also an empty socket in my computer. Before I explain a method to try
and fix it I have listed the Mixes and if they nead SWR and if so how
many 16K banks.
Note:- All mixes except MEGAMIX 3 work fine on a MASTER. (I think.)
'0 or 1' means it has a shortened version for NON-SWR BBC's.
I think the ones that nead 4 SWR banks are MASTER ONLY.
Mix Name/ Noumber of File Drive
Mix Disc SWR banks Name
MIXMANIA:-
Megamix 0 MIXI 0
Megamix 2 4 MIXII 0
Top Gun 4 TOPLOAD 2
Robocop 0 ROBMIX 2
James Whale 0 WHALMIX 2
Loadsamoney 0 LMIX1 0
Nineteen 1 19LOAD 2
MIXMANIA II vol I:-
Thunder Birds 0 or 1 FAB1 2
Housey Mix 0 or 1 HOUSE1 2
Pump Up The Bitter 0 or 1 PUMP1 2
Jack Mix 0 JACK1 2
What Time Is Love 0 or 1 LOVE1 0
Megamix 3 0 or 1 MEGLOAD 0
MC Hammer 0 UCANT 0
The Wizard 0 or 1 WIZARD1 0
MIXMANIA II vol II:-
Loadsamoney 2 0 LMIX1V2 0
Blue Pearl 0 or 1 PEARL1 0
Tonight 0 KIDDY1 0
Set Me Free 0 or 1 SET1 0
Silly Games 0 or 1 SILLY1 2
Betty Boo 0 or 1 BETTY1 2
Human League 0 or 1 HUMAN1 2
Toms Diner 0 DNAMIX1 2
COMPUTERS WITH SWR :-
---------------------
As mentioned above the reason it fails to use SWR correctly is because
it seems to just looks for an empty socket. I doubt it would find the
SWR bank if there is anything in it already but I am not sure about
that.
One way to make it work would be to buy enough ROM's to fill all your
computer's ROM sockets but this would be very expensive and I am only
joking.
I will use the nineteen remix as an example, I found out what location
in memory it was storing the SWR bank number at, I then directly poked
14 (The Correct SWR Bank Number) into that location. The procedure was
to load the file 19LOAD from drive 2 of Mixmania, then find line 180,
then change it to: 180 .found ...leave as before upto...
:CALL&910:?&92=14 The COPY key can be used to copy the part of the
line that wants leaving alone and then type in the ?&92=14 at the
position shown above, then save the file back to disc as 19LOAD.
This method works but is a bit messy so at present I am looing at a
way to modify it properly. I may have to get the program to ask the
user if they have SWR and if so what bank or banks it is in.
All the mixes that can use one SWR bank can be modified in this way,
it is not always the same line that neads changing but it is a similar
looking line that says something like IF?&92..., that part wants
changing to ?&92=14 or whatever your SWR bank number is.
If you are not confident or not sure about modifying the programs
yourself then I will modify the discs for you for a small fee of 20p
per disc, or I'll modify all three for 50p. If you would like me to
modify them for you then send the discs (with Mixmania already on them
if possible but this is not too important but if you are sending blank
discs they must be 80track double sided and FORMAT them please! If
they are not formatted they will be put at one side and will have to
wait until I have time!) Also let me know what socket your SWR is in,
ie. Watford Solderless RAM with SWR in 14L and 14H = 16K of SWR in
bank 14, also send return postage and packaging, if not enough return
postage is sent then you won't see your discs until you send me some
stamps! Also send the modifying charge of 20p per disc or 50p for all
three discs.
The address to send the discs to is at the end of this document. Don't
forget if you want all three MIXMANIAs, three discs are required and
they must be 80track double sided and the charge is only 50p for all 3
or 20p each if you don't want all 3. When I alter the loader programs
so that they will work on any SWR AND NON-SWR machine you will not
have to pay the modification fee for the new version as I will make a
note of the people who pay for this times modifiaction and they will
be entitled to a free update.
COMPUTERS WITH NO SWR :-
------------------------
You do not nead SWR for 4 of the mixes on MIXMANIA I and they do not
nead any modification, and the mixes on the MIXMANIA II discs that do
not nead any SWR at all are okay, the problem is with the mixes that
have a SWR and NON-SWR version.
If you do not have SWR then you can still hear the excellent sampled
remixes that the Yorkshire Boys have written, they have included
shortened versions of all samples for NON-SWR computers on MIXMANIA II
vol I and II but they won't always work correctly as the routine that
searches for SWR looks for empty sockets, or if you do not have an
expansion board in the computer that allows 16 ROMS to be fitted then
the routine tries to use one of the sockets that doen't even exist.
I have come up with a system that works but is a bit messy so at
present I am looing at a way to modify it properly. I may have to get
the program to ask the user if they have SWR and if they havn't it
will select the shortened versions. Please note that the mixes that
don't nead any SWR at all will not require modification.
I found the problem could be solved by altering the part of the
program that checked if a SWR bank had been found, there is a
statement in all the Mixmania II programs that says IF ?&92<16
GOTO.... , eg. the What Time Is Love mix can be modified by loading
LOVE1, list line 250, change it to : 250 A%=0:CALL&910 , then save
the program as LOVE1 and when loaded from the menu it will tell you to
press space or switch write protect off, just press space and the
shortened version will be loaded into normal RAM.
If you are not confident or not sure about modifying the programs
yourself then I will modify the two discs for you for a small fee of
20p per disc. If you would like me to modify them for you then send
the discs (with Mixmania already on them if possible but this is not
too important but if you are sending blank discs they must be 80track
double sided and FORMAT them please! If they are not formatted they
will be put at one side and will have to wait until I have time!) Also
let me know it is the NON-SWR modification that you require, also send
return postage and packaging, if not enough return postage is sent
then you won't see your discs until you send me some stamps! Also send
the modifying charge of 20p per disc. The address to send the discs
to is at the end of this document. Don't forget if you want both
MIXMANIA IIs, two discs are required and they must be 80track double
sided and the charge is only 40p for both. When I alter the loader
programs so that they will work on any SWR AND NON-SWR machine you
will not have to pay the modification fee for the new version as I
will make a note of the people who pay for this times modifiaction and
they will be entitled to a free update.
Address:- Matthew J Cocker,
155 Church Road,
Smithills,
BOLTON,
Lancs. BL1 6HH
For More Details please do phone me on:- (0204) 491291
I am in most weekdays after 7pm or any time weekends.
----------------------------------------------------------------------
Another member (4RR) has also written in with his thoughts. As these
are not as comprehensive as Matthew's, I have included them in the
Replies to Help Wanted section of the magazine.
----------------------------------------------------------------------
The never ending popularity of the Watford Solderless SWR board
continues, with a message from S Bodman asking if Andy Nibbs can
supply an article on how to fit a battery backup to the said board.
Well Andy - do you know how? - Does anybody? - If so I would very much
like to hear from you A.S.A.P.