EnterMice
Joysticks & PS/2 Mouse Interface
for Enterprise 64 & 128 computer
Contents
Introduction
The interface is designed for the Enterprise 64/128 series computer.
It enables direct connection of two joysticks in Atari standard without additional adapters. In addition, you can use a PS/2 mouse.
EnterMice is based on solutions used in the BoxSoft interface, which came with a Neos mouse(MSX protocol).
In one of the EnterMice operating modes it is fully compatible with BoxSoft. Also another of the operating modes converts the mouse movement to joystick pulsations.
A little story about Enterprise and mice
Putting a mouse to control the Enterprise is not a new and eccentric idea of a freaky retro-computing group, it was already planned by the designers of the machine. The problem was that the project was subcontracted to a modest English company named Aztec Software Ltd., that produced a disappointing job. For two main reasons: the first, it was ugly, nothing near the rounded shape of the Enterprise, and the second, it was not a real proportional mouse, it emulated the joystick movement. Also at that time Enterprise Computing Ltd. was disappearing.
But the following years the user base in United Kingdom remained very active. Some little companies where founded by Enterprise enthusiasts. New products where offered, memory expansions, tailored cables, games, utilities, Spectrum emulator, IDE controller, Eprom, expansion motherboards, serial modems, etc.
The most prolific company was Boxsoft, founded by a developer named Tim Box. They offered most of the products listed here. Bundled with a paint program named Paintbox, they marketed an adapter plus a Neos mouse with a driver included. The Neos, internally a MSX mouse, had already been successfully adapted to other 8-bit computers like the Commodore 64.
At that time only a few of 8-bit computers had a working mouse with some form of GUI. It was very difficult to sell something the user can't use widely nor even was known... Seen from today's perspective it is very clear the advantage of managing a computer with a mouse when it just stops working...
Only about a hundred of the Paintbox bundles where sold...
The Paintbox program arrived to Hungary separately. Hungarians bought the Enterprise computers knowing that they came from U.K., but not much more... and when all the Enterprises where sold the user base was abandoned like in the country of origin. Again new companies surfaced offering new products. Then a company named "A studio" begun to market the Boxsoft catalogue of products but masking them as their own and made in Hungary. One of the programs was a Paintbox version without the mouse option. It still needed the driver, but a capped version. At the other side of the Iron Curtain nobody know ever about the Neos mouse.
Later on Hungary it was offered a serial card expansion for the Enterprise, thanks to the genius of a team of Hungarian developers, Gyula Mészáros for the hardware, and László Haluska (HSOFT) for the software. HSOFT took the capped "A studio" mouse driver and modified it to suit the serial interface with a Mouse Systems mouse, later they wrote the built-in driver of the EPDOS 2.x system.
This was old history, but in recent years with WWW, Internet and globalization, some of the old artefacts Boxsoft+Neos where found and all the pieces of the puzzle begun to fit.
A real proportional mouse fitted to an Enterprise could be possible at last, from the old promises on the adverts of Enterprise Computers Ltd.
The new Entermice interface that is presented here is based on the works of the Boxsoft team, but adapted to new times and added more new options. Is a miracle what Tim Box achieved with only a few logical gates and diodes. And over the hardware, the driver was very well written by D. Rabson, Andrew Fitter and Andrew Richards. With little modifications is the same driver that will be used with the Entermice adapter.
The principal problem interfacing the Enterprise is that connectors and signals are far from being a joystick-mouse standard. Little edge connectors that can be accidentally plugged upside down, commons pulled to +5v for the buttons when normally 0 volts is used, lack of protection of the return of the signal when two or more buttons are pressed, no way to send information or state to the controller, and probably some more issues.
What they did with cheap components now has been redesigned and improved with two programmable chips and other modern details. One of the chips, a Xilinx, is in charge of the pinout and signals conversion to the Atari standard of game connectors. The original Boxsoft only standardized the first controller port, that was used to connect the Neos mouse or a standard joystick, but not both at the same time. On the present project two joystick ports have been provided and they don't interfere with the mouse port.
The Neos/MSX mouse is not widely found today so, a PS/2 to MSX conversion adapter has been implemented. It is driven by a powerful 12 MHz Atmel AT89C4051, able to adapt itself to the frequency of the Z80 processor installed on the Enterprise. With this chip and the proper coding it has inside, the Entermice can work the same on a 4 MHz EP than on a supercharged 10 MHz one.
Also the mouse reading protocol has been expanded following Prodatron and NYYRIKKI's new extended MSX protocol so it can send information about an up to five buttons wheel mouse, if present. It will be soon completely compatible with SymbOS (Actually only in Boxsoft mode, see the features section about how to set this mode)
General description
Important
Do not connect the interface to the computer when the power is on !
If when you connect the interface your computer does not start up properly or behaves abnormally, it must be switched off immediately !
Check whether the interface is connected correctly and try again.
Mouse and joysticks can be connected and disconnected while the computer is power on, but this is not recommended. It is safer to perform any connection with the power disconnected.
Connecting to a computer
The interface board should be connected at the same time to 3 edge connectors on the back of your Enterprise: Control 1, Control 2 and Serial.
It can be plugged only on one way, but it may happen that the contact pins do not centered on edge connectors and contact between them is not stable.
Then, the computer and/or the interface may not work properly.
Properly connected, the interface works right after turning on the power.
After turning on a self-test is performed, during which both LEDs flash 3 times (regardless of the state of dip-switch 3).
Features
The interface can operate in several modes. To configure it a five sectional dip-switch is used.
The configuration settings can be changed during operation of the interface. You do not have to restart your computer.
Below is the description of all possible settings.
DS1 | DS2 | Work mode |
---|---|---|
ON | ON | EnterMice native mouse mode |
OFF | ON | BoxSoft compatible mouse mode |
OFF | OFF | EnterMice joystick mode (instead of Joystick 1) |
ON | OFF | not used (exactly EnterMice as joystick on KB K column) |
Joystick 2 always works the same regardless of the interface operating mode selected.
DS3 | LED status |
---|---|
OFF | LED status disabled |
ON | LED status enabled |
Joystick emulation mode configuration
DS4 | Sensitivity |
---|---|
OFF | Normal |
ON | High |
DS5 | Diagonal correction |
---|---|
OFF | Disable |
ON | Enable |
Diagonal correction improves the precision of joystick simulation diagonal movements, at the expense of a slight decrease in speed.
Troubleshooting
Keyboard issue
During creating the EnterMice, accidentally we discovered a fairly serious error in the design of the Enterprise.
Totally do not mind, if nothing is connected to the ports Control 1 and Control 2.
However, that EnterMice uses them.
It's about interferences on KB0..KB9 ports from keyboard.
If at one time is pressed only one key, then there is nothing wrong with (first figure).
However, if you press two keys simultaneously in the same column, the signal from the selected line will be transferred also to the line of second key (figure two).
In the Enterprise missing diodes to separating the rows of the keyboard !
Electrically nothing will happen (inside LS145 decoder has open collector outputs), but causes errors when reading from the external ports Control 1 and Control 2.
In order to eliminate the cause should be add diodes to each row of keys the Enterprise, to press more than one key does not cause "collisions" (third figure).
I prepared a draft of the PCB-fixing, but has not been tested.
Microsoft Optical Mouse
MS Optical Mouse, in opposite to other mouses, works with EnterMice, but in its case, you can not use hot-plug feature.
After connecting the mouse to EnterMice during operation, you need momentarily short the RESET pin-header on the interface (it resets only interface, does not the computer).
Technical specification
Joystick port pinout
pin | signal |
---|---|
1 | Up |
2 | Down |
3 | Left |
4 | Right |
5 | Fire 3 |
6 | Fire 1 |
7 | +5 V |
8 | GND |
9 | Fire 2 |
Control Map
J column (bit 0) | K column (bit 1) | L column (bit 2) | |||||
---|---|---|---|---|---|---|---|
JM=0* | JM=1* | JM=0 | JM=1 | JM=0 | JM=1 | ||
Control 1 | Row 0 Fire | Joy 1 Fire 1 | Mice Left Btn | Mice Left Btn or Joy 1 Fire 2* | Joy 1 Fire 2 | Mice Right Btn or Joy 1 Fire 3* | |
Row 1 Up | Joy 1 Up | Mice D0 | Mice D0 | spare | spare | spare | |
Row 2 Down | Joy 1 Down | Mice D1 | Mice D1 | spare | spare | spare | |
Row 3 Left | Joy 1 Left | Mice D2 | Mice D2 | spare | spare | spare | |
Row 4 Right | Joy 1 Right | Mice D3 | Mice D3 | spare | spare | spare | |
Control 2 | Row 5 Fire | Joy 2 Fire 1 | Joy 2 Fire 2 | Joy 2 Fire 3 | |||
Row 6 Up | Joy 2 Up | spare | spare | spare | spare | ||
Row 7 Down | Joy 2 Down | spare | spare | spare | spare | ||
Row 8 Left | Joy 2 Left | spare | spare | spare | spare | ||
Row 9 Right | Joy 2 Right | spare | spare | spare | spare |
* Mouse buttons have higher priority * JM=0 (DS1 ON) native EnterMice mouse mode JM=1 (DS1 OFF) joystick emulation & BoxSoft compatible mode
Sega twister
for connect the Sega six-button pad
Sega Six Button Controller Hardware Info
Interface Protocol of SEGA MegaDrive's 6-Button-Controller
pin | Select = Low | Select = High | Select = pulse-3 |
---|---|---|---|
1 | Up | Up | Button Z |
2 | Down | Down | Button Y |
3 | GND | Left | Button X |
4 | GND | Right | not used |
5 | +5V | ||
6 | Button A | Button B | not used |
7 | Select | ||
8 | GND | ||
9 | Start | Button C | not used |
Information for developers
EnterMice timings
The firmware of EnterMice is optimized for the cyclic reading with 50 Hz frequency (video IRQ).
Default reading cycle | 20 ms |
Waiting time to perform self-test the PS/2 mouse (timeout) | ca. 2000 ms |
Time of collecting the PS/2 mouse data | max. 12 ms |
Time from change state of RTS signal to issue data (nibble) for reading | 25 μs |
Standby time for the next reading (counting from data issue) | 14 μs |
Time from read the last nibble of data to reset the nibble counter (timeout)* | 1500 μs |
Default mouse polling time in joystick emulation mode | 30 ms |
Mouse polling time in joystick emulation mode when mouse doesn't move (minimize polling delay) | 12,5 ms |
* After this time is performed another mouse data polling.
Data buffer
Data buffer in EnterMice has a size of 16 bytes.
Currently is used only half. The remainder may be used in the future.
Byte | High nibble | Low nibble | Content | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | ||||
0 | X value | signed int (positive is moved left) | BoxSoft | |||||||||
1 | Y value | signed int (positive is moved up) | ||||||||||
2 | 0 | 0 | 0 | 1 | 0 | Btn5 | Btn4 | Btn3 | Protocol identyfication & buttons 3,4,5 state | Extended protocol | ||
3 | Z value | signed int (positive is wheel moved up) | ||||||||||
4 | ExCnt | Mouse ID | Extra bytes available to read (include this) & PS/2 mouse ID | EnterMice extension protocol | ||||||||
5 | Hw ver. mj. | Hw ver. mn. | Hardware version (major.minor) | |||||||||
6 | Fw ver. mj. | Fw ver. mn. | Firmware version (major.minor) | |||||||||
7 | Device ID | EnterMice ID is 5Dh |
Mouse reading
; Here begin the Neos mouse reading | ||
ld hl,X_REL | ; first byte | |
ld a,2 | ; RTS low | |
out (0B7h),a | ||
ld b,8 | ; long delay | |
call WAIT | ||
call READ_4BIT | ; read four higher bits | |
rld | ; push them in (HL) | |
xor a | ; RTS high | |
out (0B7h),a | ||
ld b,5 | ; short delay | |
call WAIT | ||
call READ_4BIT | ; read four lower bits | |
rld | ; push them in (HL) | |
ld hl,Y_REL | ; second byte | |
ld a,2 | ; RTS low | |
out (0B7h),a | ||
ld b,5 | ; short delay | |
call WAIT | ||
call READ_4BIT | ; read four higher bits | |
rld | ; push them in (HL) | |
xor a | ; RTS high | |
out (0B7h),a | ||
ld b,5 | ; short delay | |
call WAIT | ||
call READ_4BIT | ; read four lower bits | |
rld | ; push them in (HL) | |
;<======Here will be added the future Wheel and three spare buttons reading. SECOND TENTATIVE | ||
ld hl,SW_Z_STATUS | ||
ld a,2 | ; RTS low | |
out (0B7h),a | ||
ld b,5 | ; short delay | |
call WAIT | ||
call READ_4BIT | ; read four higher bits | |
and 15 | ||
cp 1 | ; IF THIS NIBBLE=0001 THEN THE MOUSE IS IN EXTENDED PROTOCOL | |
jr z,CONTINUE_READ | ||
xor a | ; RTS high | |
out (0B7h),a | ;IGNORE THAT NIBBLE | |
ld (hl),0 | ; we don't need old values | |
jr STOP_READ | ||
CONTINUE_READ: | ||
xor a | ; RTS high | |
out (0B7h),a | ||
ld b,5 | ; short delay | |
call WAIT | ||
call READ_4BIT | ; read four higher bits, the three lower bits are the buttons. They come ready to store | |
push af | ; push them in stack. they are in the lower nibble. | |
ld a,(hl) | ; | |
push af | ;save the Z counter for later. | |
ld a,2 | ; RTS low | |
out (0B7h),a | ||
ld b,5 | ; short delay | |
call WAIT | ||
call READ_4BIT | ; read four bits | |
rld | ;we need z displacement in 8 bit | |
xor a | ; RTS high | |
out (0B7h),a | ||
ld b,5 | ; short delay | |
call WAIT | ||
call READ_4BIT | ; read four lower bits. Z displacement | |
rld | ; push them in (HL) ;NOW WE HAVE Z displacement in (hl) | |
pop af | ; restored Z counter to "a", but we have garbage on high nibble | |
and 00Fh | ||
bit 3,a | ||
jr z,SIGN_DONE | ||
or 0F0h | ||
SIGN_DONE: | ; now we have the sign extended to 8 bits on "a" | |
add a,(hl) | ||
cp 128 | ; positive or negative? | |
jr c,POSITIVE | ||
cp 248 | ; lower than -8? | |
jr nc,FINISHED | ; | |
ld a,248 | ; -8 is the bottom | |
jr FINISHED | ||
POSITIVE: | ||
cp 8 | ; higher than 7? | |
jr c,FINISHED | ||
ld a,7 | ; 7 is the top | |
FINISHED: | ; the excess of 7 or -8 has been wiped | |
ld c,a | ; save Z addition on c | |
pop af | ; retrieve the buttons status. They are now on first nibble of a | |
rld | ; buttons stored | |
ld a,c | ; we only need the first nibble of Z counter addition | |
rld | ; the spare buttons status and the Z counter are now in SW_Z_STATUS | |
STOP_READ: | ||
xor a | ; recall buttons on row 0 | |
out (0B5h),a | ||
in a,(0B6h) | ; read Mouse buttons | |
and 7 | ; mask | |
xor 7 | ; flip them all as on Enterprise a pressed key is 1 and released 0 | |
rl (hl) | ; Get ready the bit 7 of "hl" register pair. Inside is SW_Z_STATUS, variable number 190 | |
srl a | ; This is the very FIRST "srl a". The button status is now in the carry flag | |
; secondary button of Boxsoft is read on J column. Primary button of Entermice is read on K column | ||
push af | ||
ld a,(INPUT_DEVICE) | ||
cp 3 | ; Boxsoft interface mode buttons | |
jr nz,L_BUTTON | ||
pop af | ; We need the value of "a" and "f" registers. Carry flag still stores the value of secondary button | |
rr (hl) | ; secondary button goes to bit 7 of SW_Z_STATUS, variable number 190 | |
srl a | ; Primary button of Boxsoft is on J column. This is the second "srl a" | |
JR MAIN_BUTTON | ||
L_BUTTON: | ; Entermice interface mode buttons | |
pop af | ; retrieve the value of register "a". "f" is disposable, soon we will load the button on carry flag | |
push af | ; I still will need later the register "a" value | |
srl a | ; two "srl a" because the secondary button of Entermice is read on L column | |
srl a | ; the proper button status is now in the carry flag | |
rr (hl) | ; secondary button goes to bit 7 of SW_Z_STATUS, variable number 190 | |
pop af | ; retrieve the value of register "a" just after the FIRST "srl a" | |
MAIN_BUTTON: | ||
and 1 | ||
ld (FIRE_STATUS),a | ; EXOS Variable 188. K column if Boxsoft or L column if Entermice | |
call sub_C3A6 | ; this is the "corrections and drawing" routine where the "velocity" 1.1 modification was made | |
ld a,(X_REL) | ||
ld c,a | ||
ld a,(Y_REL) | ||
or c | ||
ret | ||
WAIT: | ||
nop | ||
nop | ||
nop | ||
dec b | ||
jr nz,WAIT | ||
ret | ||
READ_4BIT: | ; I split the routine in two to not put more processor time | |
ld b,4 | ||
ld d,0 | ||
ld a,(INPUT_DEVICE) | ||
cp 3 | ||
jr z,L_COLUMN | ||
K_COLUMN: | ||
ld a,b | ||
;inc c | ; this is not necessary | |
out (0B5h),a | ||
in a,(0B6h) | ||
;ld c,a | ; this is not necessary | |
rra | ; data read from K column | |
rra | ||
rl d | ||
djnz K_COLUMN | ||
jr CONTINUE | ||
L_COLUMN: | ||
ld a,b | ||
;inc c | ; this is not necessary | |
out (0B5h),a | ||
in a,(0B6h) | ||
;ld c,a | ; this is not necessary | |
rra | ; data read from L column | |
rl d | ||
djnz L_COLUMN | ||
CONTINUE: | ||
ld a,d | ||
ret |