INTRODUCTION Matured computer hardware (e.g. Arcade PCBs, home computers, etc.) usually don’t have a debug interface, nor do they provide an easy way to alter the firmware. This firmware in form of an integrated circuit in a DIP-package ROM and/or EPROM is fitted on the PCB. This blog introduces a EPROM EMULATOR which can be… Read more EPROM EMULATOR SHIELD FOR ARDUINO MEGA 2560
Category: C64 & more
Floppy Drive Deep Dive
1541 Memory Map 1571 Memory Map 1581 Memory Map ‘Boost Your 1571’ Memory Map DOS sector layout HW Bit Timing Byte Ready Sync Pinout Port A VIA1 Data Register Port B VIA1 Data Register Port B VIA2 Data Register Auxiliary Control Register Peripheral Control Register Interrupt Flag Register Interrupt Enable Register Port A CIA Data… Read more Floppy Drive Deep Dive
FLOPPYmate hardware
INTRODUCTION FLOPPYmate requires an interface between the USB and the serial IEC bus. The hardware described in this Blog provides an interface (SER2IEC) between UART and the serial IEC bus for peripheral devices like disk drives 1540, 1541, 1570, 1571 and 1581. UART interface Decide on one of these UART interface types for your FLOPPYmate:USB… Read more FLOPPYmate hardware
C64 Track Display 1541, 1571
INTRODUCTION When working with a 15X1 floppy drive, it comes in quite handy to know the track, the drive is currently accessing. This blog presents a kind of drive-modding for 15X1 afficionados. FEATURES SINGLE IC GAL22V10 SOLUTION 2 DIGITS LATCHED BCD INTERFACE (0 TO 79) LET’S GET STARTED Circuit Description The State Machine in this… Read more C64 Track Display 1541, 1571
FLOPPYmate software
OVERVIEW The FLOPPYmate application is a convenient tool for backing up individual PRG files and/or whole disks, sending DOS commands, as well as checking the drive’s spindle speed. Furthermore the data of a whole track can be displayed as binary and GCR. It’s the answer to how to fast backup and restore 1541, 1571 and… Read more FLOPPYmate software
6522 Fast Serial Driver
INTRODUCTION FLOPPYmate requires a high speed data transfer to read/write an entire track within a single disk revolution. This task requires a data transfer rate of at least 40KB/s. High speed (>8 KB/s) data transfer from or to a 1541 Disk Drive is commonly achieved using a 8 bit parallel cable connected to Port A… Read more 6522 Fast Serial Driver
C64 PLA Replacement
INTRODUCTION Troubleshooting a dead C64 often reveals a faulty PLA IC as the root cause. The PLA does the address decoding and bank switching. SIGNETICS 82S100 (later PHILIPS PLS100) Bipolar Programmable Logic Arrays were used in early revisions of the C64 Mainboard assy, which were then replaced by MOS 8700-001 and MOS 906114-01. This blog… Read more C64 PLA Replacement
C64 MOS 8701 Replacement
INTRODUCTION The C64 can only work properly with stable clocking. In a C64 II the MOS 8701 IC generates two major clocks and maintains the fixed frequency and phase relationship. COLOR_CLK is the main crystal oscillator clock and DOT_CLOCK is derived thereof. This blog presents a replacement circuit for the MOS 8701 IC. Orginal MOS… Read more C64 MOS 8701 Replacement
Boost Your 1571 Floppy Drive
INTRODUCTION Taking a closer look at the 1571 disk drive reveals that it contains the major ICs needed to build a 1581 compatible disk drive. This blog describes how to boost a 1571 so that it can turn into a 1581 with the flip of a switch. FEATURES High compatibility 1581 disk drive emulation Use… Read more Boost Your 1571 Floppy Drive