... case as port #FF that was usually used for reading the floating ...

... fetch op, 3 for reading the port and 4 for write to ... instruction executes - it reads the port between 5th and 8th t ... "in" instruction, but after the port has been read. We waste ...

... ; b=buffer size, c=RS232_DTA port
ld de,0x8000 ; masks ...
nop

;; start reading data bits
in a ...

... ),a ; send pattern 1 to port 7ffd
ld b,0xfe ...
in a,(c) ; acc=port fedf
ld hl,0 ... />
test is needed because reading the mouse status like this ...

... problems you can read a port immediately after a HALT (since ... be guaranteed not to be reading memory immediately after an interrupt ... what the Spectranet CPLD version reading has to do as the ...

As i can understand, this document is only about delays that appeares with 254 port read/write. But delays itself can not brings to stopping programs. I think my problem is in wrong generating flags or wrong bits 7, 6, 5 of port in time of reading.

... 1 instead of a floppy port.

essentially change the ... , the device would allow for reading as well writing in fact ...

... It checks whether writing to port 0x3ffd activates memory paging. ... partial
;; decoding of "port 0x7ffd"[/code]

... the 0x7ffd, 0x3ffd and 0xbffd port checks?[/quote]

reading[/i] from that port induces memory paging ...

... . It checks whether writing to port 0x3ffd activates memory paging. To ... the partial
;; decoding of "port 0x7ffd"[/code][/quote]

reading[/i] from that port induces memory paging on ...

... which plugs into the user port, and saves/loads at 4 ... ][/url].

Edit: From reading the patent application, it sounds ...

... stuff next then, I guess - port reading/writing, and tape traps or ...

... line-for-line port (one story has him reading the Z80 over ...

... in reality it meant reading from port C? Or maybe that ... problem: when reading keyboard, the upper half of port address matters ... with future hardware since those port addresses are already reserved? ... address space by always reading from port 0xFE doesn't seem ...

... : when reading keyboard, the upper half of port address matters ... says that every even port address identifies the ULA ... with future hardware since those port addresses are already reserved? ... quote]
One last thing. Port 0xFE, among other things, identifies ...

Here's one horrid assembler implementation of keyboard emulation..

[code]
SetShiftCtrlState PROTO
GetSpeccyKeyState PROTO

.data?
keyboard_state BYTE 256 dup (?)

keyboard_hasfocus BYTE ...

... at bit 7 of port FFh is not the ... The computer has to keep reading the monostable value while it ... source code, I think that port FFh offers two things: ... 0. The routine reads port FFh, stores bit 0 ... routine changing the FFh port by the FEh port.

...

... collide with kempston port if I use reading from port FF0D of any ...

... understanding them. If the same port serves two purposes (it both ... ]

You're confusing reading with writing. The ULA maintains ... when you read an even port.

D ...

... mimic the responses to the port reads based on the state ... .

Might be worth reading through all the previous posts ...

... period and interrupts were disabled, reading from appropriate ports always resulted ... know some games relied on port reads to the point where ... assume that reads from keyboard port return FF right after snapshot ...

... Commodore via its RGB(?) port and there is another ... into the other video port and flicking the switch ... had to resort to reading the manual and found:< ... first "open" the printer port and then send information ... to that port where the printer is ...

... 's get to port reading and keyboard handling. Here's port reading (all IN ...

... it's not quite true. Reading from 0x7ffd returns the floating ... read videoram, CPU continue in reading but data bus contain #FF ... ).

Also "attribute port" 255 can return always value ... Last version of +2 ignore reading from port 7FFD - On this models ...

... anything pluggable to an IDE port. It supports CF and SD ... emulates a disciple floppy drive (reading/writing) and others let you ...

... ago I rewired the SJS port to make it compatible with ... for your help. I remember reading about that bug some years ...

... rain/snow effect and ignore reading of port #7FFD)

... + modded to have a tape port, with a Symbiface 2 RAM ... if there is a mod reading this can you possibly add ...

... spent with Spectrum games, and reading old magazines and such, the ... have the odd popular arcade port here and there).

... . Detecting by writing and the reading after. Disabling by sending 000 ... 0) to these 3 bits port.
2. The scanline skips ...