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EnigmA Amiga Run 1996 June
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EnigmA AMIGA RUN 08 (1996)(G.R. Edizioni)(IT)[!][issue 1996-06][EARSAN CD VII].iso
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addzrr2s.lha
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zorro2slot.txt
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1996-04-11
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*******************************************************************************
* *
* AddZorro2slot *
* *
* Subtitle: " HOW I ADDED A 100 PIN ZORRO 2 SLOT (FOR A PICASSO II) *
* TO MY A500, KEEPING INTACT THE 86 PIN EXPANSION PORT " *
* 4/4/1996 *
* *
*******************************************************************************
Author
My name is Gabriele Peterle, and I'm an informatic engineering student at the
Padova university.
Excuse me for my poor english but I learn it by myself; I hope you'll be able
to understand.
If you want to contact me for explanations or comments you can write to my
e-mail address:
ray@maya.dei.unipd.it
or snail-mail:
Gabriele Peterle
viale dei Colli 10/a
37128 Verona
ITALY
Copyright and Distribution
This project is freeware, even because I invented nothing; I only read the
manuals and the A500 and A2000 schematics.
You can send me whatever you want, just to tell me if you liked it or not.
It can be distributed everywhere but please keep the archive intact.
History
I own my Amiga 500 since 1988.
As the AGA Amigas were available I was not so excited. The specs was not so
great compared to my system ( and compared to the "soon upcoming" AAA
chipset), so I decided to wait.
You all know what happened a couple of years later ....
Now I'm here waiting for a PPC Amiga, but in the meanwhile I added to my
trusty 500 the only thing it missed: 24 bit graphic !
There are a lot of graphics boards for A2000, but none for A500, so I
compared the schematics of the two systems and I added a full (?) 100 pin
Zorro2 slot to the 86 pin expansion port of the A500 (NOTE: This hack allows
to ADD a 100 pin Zorro2 slot keeping intact the 86 pin expansion port !!!!).
Limits
My system consists of:
Amiga 500, motherboard rev.5 (originally with kickstart 1.2)
A501 0.5 MB expansion memory in the trapdoor
8375 Agnus (1 MB chip ram)
ROM 2.04 (soon 3.1)
Hardital Big Bang accelerating board with 68030/882 33 MHz, 8 MB 32bit
FAST RAM, inserted in the 68000 socket.
Hardital Synthesis SCSI controller with 80+170 MB Quantum Harddisks
inserted in the 86 pin expansion port ( NOT DMA )
Picasso II graphic board in the added 100 pin Zorro2 slot.
This system works great since over 1 month.
If I'm not wrong the A1000 has the same 86 pin expansion port so this hack can
be adapted to work with this too.
I give NO WARRANTY this hack will work with other configurations; you had to
try by yourself and at YOUR OWN RISK !!!
If you do something wrong the consequences are unpredictable: maybe your Amiga
won't work and removing the hack will solve the problem, but it's possible
that you BLOW UP your computer and I have no responsibility !!!!
I chose a Picasso II, so this project is realized around it.
This hack uses NO EXTRAS CHIPS (in particular there's no Buster), thus this
slot can work with other than graphics boards but I think only one board can
be DMA (I have some doubts it will work with GVP boards, because they use DMA).
Also a Firecracker24 worked good with this hack.
Theoric realization
With reference to the included pic, the straight lines are really used by my
Picasso II board, dotted lines instead are possible links but I didn't
tested it.
The description is referred to my configuration; you change my SCSI controller
with your device inserted in the 86 pin expansion port, and my Picasso II with
the board you want to insert into the new slot.
Here I list the 100 pin Zorro 2 slot signals on the left, and the corriponding
signal taken from the A500 on the right. If in your user manual there are the
schemes, it can be useful to give it a look sometimes. Better if you can
compare the A2000 and A500 schemes.
There are some references to another hack I found on Aminet called 2000slot.lha
which can be found in the hard/hack directory (but this hack only allow to
_transform_ the 86 pin expansion slot to a 100 pin Zorro 2 slot); anyway it
can be useful to give it a look.
ZORRO 2 signals (the initial number Where to find it on A500 (the initial
is the pin number on the 100 pin number is the pin number on the 86 pin
Zorro slot) expansion port)
1 GND 1 GND
2 GND 2 GND
3 GND 3 GND
4 GND 4 GND
5 +5 V 5 +5 V
6 +5 V 6 +5 V
7 LOCAL_OWN* ??? (not used by Picasso)
This is an output signal to the Buster
chip probably used for DMA.
8 -5 V Some power supply (not used by Picasso)
This voltage is not present in the A500
power supply !!!
In another hack (2000slot.lha) the
author used the pin #8 of the expansion
port but this gives -12 V !!!!!
Watch out !!!!
9 SLAVEn* ??? (used by Picasso, but I leave it not
connected).
This is an output signal to the Buster
chip probably used for DMA.
10 +12 V 10 +12 V
11 CONFIG_OUT* this signal must go as CONFIG_IN* of the
next board (I connected this to pin 12
of my SCSI controller inserted in the
expansion port). See pic.
12 CONFIG_IN* 12 CONFIG*
NOTE: this signal MUST go only to one
board (the Picasso) so you MUST break
the connection between the #12 pin of
the expansion port and the #12 pin of
the board inserted into it. See pic.
13 GND 13 GND
14 C3* 14 C3* (not used by Picasso)
15 CDACB 15 CDAC (not used by Picasso)
16 C1* 16 C1* (not used by Picasso)
17 OVR* 17 OVR* (not used by Picasso)
18 XRDY 18 XRDY
19 INT2* 19 INT2* (not used by Picasso)
20 -12 V 8 -12 V (not used by Picasso)
21 BA5 21 A5
22 INT6* 22 INT6* (not used by Picasso)
23 BA6 23 A6
24 BA4 24 A4
25 GND 25 GND
26 BA3 26 A3
27 BA2 27 A2
28 BA7 28 A7
29 BA1 29 A1
30 BA8 30 A8
31 BFC0 31 FC0 (not used by Picasso)
32 BA9 32 A9
33 BFC1 33 FC1 (not used by Picasso)
34 BA10 34 A10
35 BFC2 35 FC2 (not used by Picasso)
36 BA11 36 A11
37 GND 37 GND
38 BA12 38 A12
39 BA13 39 A13
40 EINT7* 40 IPL0* (not used by Picasso)
41 BA14 41 A14
42 EINT5* 42 IPL1* (not used by Picasso)
43 BA15 43 A15
44 EINT4* 44 IPL2* (not used by Picasso)
45 BA16 45 A16
46 BEER* 46 BEER*
47 BA17 47 A17
48 VPA* 48 VPA* (not used by Picasso)
49 GND 49 GND
50 E 50 E (not used by Picasso)
51 VMA* 51 VMA* (not used by Picasso)
52 BA18 52 A18
53 RST* 53 RST* (not used by Picasso)
54 BA19 54 A19
55 HLT* 55 HLT* (not used by Picasso)
56 BA20 56 A20
57 BA22 57 A22
58 BA21 58 A21
59 BA23 59 A23
60 BRn* These 2 signals |--->60 BR* (not used by Picasso)
61 GND are used if the | 61 GND
62 BGACK* board uses DMA | 62 BGACK* (not used by Picasso)
63 BD15 (Direct Memory | 63 D15
64 BGn* Access) |--->64 BG* (not used by Picasso)
65 BD14 65 D14
66 DTACK* 66 DTACK* (not used by Picasso)
67 BD13 67 D13
68 READ 68 R/w*
69 BD12 69 D12
70 BLDS* 70 LDS*
71 BD11 71 D11
72 BUDS* 72 UDS*
73 GND 73 GND
74 BAS* 74 AS*
75 BD0 75 D0
76 BD10 76 D10
77 BD1 77 D1
78 BD9 78 D9
79 BD2 79 D2
80 BD8 80 D8
81 BD3 81 D3
82 BD7 82 D7
83 BD4 83 D4
84 BD6 84 D6
85 GND 85 GND
86 BD5 86 D5
87 GND 85 GND
88 GND 85 GND
89 GND 85 GND
90 GND 85 GND
91 GND 85 GND
92 7 MHz 68000 pin #15 (not used by Picasso)
93 DOE ??? (not used by Picasso)
I think this signal is a delayed AS*
(pin #74). The author of 2000slot used
+5 V (pin #5 or #6). I think it is used
by DMA boards
94 BUSRST* I first tried the RST* signal (pin #53)
It worked fine in 68000 mode, but I had
big troubles in 68030 mode (yellow
screen with flashing led).
I solved all my problems using the A500
RESET* signal. I took this from the #11
pin of the U37 component of my rev.5
motherboard (it's a 74LS32 (NAND gates))
It is located under the internal floppy
drive.
If in your motherboard isn't there such
a component, you can try to follow the
RST* signal track and see if it passes
through some AND/NAND/OR... gate(s) and
exits unchanged (AND with +5v, or OR
with GND, ...) and then use the output
as BUSRST*.
95 GBG* 64 BG* (not used by Picasso)
96 EINT1* ??? (not used by Picasso)
97 not connected not connected
98 not connected not connected
99 GND 85 GND
100 GND 85 GND
Almost all the links are taken (in parallel) directly from the 86 pin port, so
you can solder a wire between the two corrisponding pins (one on the Amiga,
the other on the new slot).
The CONFIG_IN* and CONFIG_OUT* signals are connected "serially": the CONFIG_IN*
from the 86 pin expansion port is connected to the Picasso's CONFIG_IN* pin;
the CONFIG_OUT* signal from the Picasso is connected to the CONFIG_IN* of the
board inserted in the 86 pin expansion port (e.g. my SCSI controller);
Probably it's possible to change the config order (first the SCSI controller,
then the Picasso) but my SCSI board has no CONFIG_OUT* signal.
NOTE: it's important that the CONFIG_IN* of the 86 pin expansion port goes to
only one board or you'll have auto-configuration conflicts !!
The BUSRST* signal is taken from a 74LS32 chip on the A500 motherboard (under
the internal floppy drive); the 68000 RST* signal makes there a NAND (with
negated inputs) with 0, thus it exits unchanged but more stable (and a little
delayed), and then goes to the #94 pin of the Zorro 2 slot.
I tried, before, to use directly the RST* signal as BUSRST* but I had some
conflicts between the Picasso and the accelerating board during the reset
sequence (I think both boards tried to autoconfig itself in the same time
and/or in the same addresses).
Practical realization.
I rate the realization quite simple if you are expert with soldering and
testing electric circuits, quite hard (and dangerous for your Amiga) if you
have no idea about what you're doing.
You had to be very patient and make everything slowly with calm.
NOTE: my project uses NO EXTRA CHIPS !!!
It was impossible to me to found a 100 pin slot.
I went to a computer reparation center and there I obtained, for free, a
non-working 286 motherboard. I rip off from it 2 ISA (?) slots (62 pins
each); I cut it in the way that they can be aligned to form one 100 pin slot
(once the Picasso is inserted they won't move).
Then I used a 50 wires flat-cable (two 9 cm long pieces, aligned; keep these
cables as short as possible !) to make the connections between the 100 pin slot
and the 86 pin expansion port.
Note that the numer one pin on the A500 is to the rear of the upper side of
the motherboard, but the number one pin of the 100 pin slot is (looking at it
from above) to the rear of the left side.
__________ _________
| |
| |
| _ |
|_ #1 pin--->| |<---#2 _|
SCSI |<--- #1 pin | | #1 pin-->| A500
controller | | | | expansion
(upper | | | | port
side) | | | | (upper
| | | | side)
_| | | |_
| #99--->|_|<---#100 |
_________| |__________
100 pin slot
(top view)
I made all the solders in the "vias" (holes which bring a track from a face to
the other) on the SCSI board; the SCSI board is inserted, with its slot, in
the expansion port and the flat cables bring the signals to the new Zorro slot.
If you can't do like me, probably you must think about some other way to
connect the boards; you can make a connector which duplicates the signal of the
expansion port (from each pin start two wires, one for the 100 pin slot and the
other for the SCSI controller).
Other wires can be used for the BUSRST*, 7MHz, -5V,... connections.
You have to make all the connections your new Zorro 2 board requires.
CHECK EVERYTIME IF THE CONNECTION ARE NOT FAULTY AND THERE ARE NO SHORT
CIRCUITS !!!
Credits, thanks and greetings go to:
My brother Leonardo, for his insistence which push me to conceive and realize
this project.
Dr. Segio Congiu, my Electronic Computers professor, who made me understand
what I was doing.
My friends Massimiliano Farnea, Zeno Montresor, Michele Bianchi and
Eugenio Perinelli for their technical,theorical and moral support.
Piergiorgio Sartor and Paolo Canali, ever ready and gentle to answer to my
questions.
Greetings to:
The Amiga community of the Padova University, the worldwide Amiga community,
the Amiga Report staff, the Amiga Technologies team, and everyone who knows me.
Happy hacking!!
Gabriele
