1541 Ultimate

Technical Info
ROM	2 MB flash
RAM	32.5 MB
Hardware features	3 Buttons - Freeze, Reset and 1541U Freeze
Manual	PDF: 28 pages from 1541ultimate.net; PDF: 2 pages scan of suplied documentation sheet;
CRT ID	None
Programming	See 1541ultimate.net

	This article as well as WiPeD 1541 Ultimate are describing the v1 version of this nice hardware - v2 is already due and 1541 Ultimate-II is the current revision. This article needs an update badly - for recent news and data please check: 1541ultimate.net

1541U is one of the ultimate cartridges for the C64 and regular checks at

1541ultimate.net

are a strict requirement for any C64 cartridge lover. Since the 1541U emulates a range of freezer cartridges and allows re-flashing them it is a perfect platform for testing ROMs on the real machine. Cartridge emulation is pretty good and should suit most requirements. This emulation also made the 1541u enter the charts here. There are some problems left as with any other hardware but since this baby can be updated and firmware is publicly available we see a bright future for it.

The awesome list of features below speaks for this fine C64 hardware extension by itself just one important info appears to be missing: the stereo audio output mentioned towards the end of the hardware specs allows to connect speakers to the 1541U. The speakers will then produce original 1541 sound including compositions like 1541-Music or own tracks done with e.g. Drive Composer.

Mostly from the 1541Ultimate Website:

Features

Full emulation of a real Commodore 1541 diskdrive.
- Uses .D64 files stored on SD card
- Supports .G64 files as well (Read only)
- Configurable ID
- Configurable ROM (1541/1541C/1541II or custom)
- RAMBOard memory expansion (16K)
Secondary 'IEC-drive' for direct access to FAT filesystem
- Can be used in stand alone mode to mount disks into the emulated 1541.
FAT/FAT32 support, with sub-directories and long filenames
Supports SD V1.1 cards as well as SD V2.0 in High Capacity mode (SDHC)

C64 cartridge emulation:
- Final Cartridge III
- Action Replay
- Retro Replay
- Super Snapshot
- Turbo Assembler w/ Codenet
- Ocean
- 8k/16k game

for details see CRT_ID

Commodore 1750/1764 REU
- REU Compatible
- Size selectable from 128K up to 16 MB
- Can be combined with Retro Replay and SuperSnapshot compatible roms
Integrated RR-net compatible Ethernet port
- Available as an option on a new order only!
- No flimsy stackup board, but fully integrated.
Flexible freezer menu
- select, mount, create D64 images, browse disk images
- create new directories, delete files
- Ultra fast DMA load of single file programs (directly from SD / from a .D64 with automount and from a .T64 file)
Configuration screen, with resident settings
Load of last disk on power up
'Stand-alone mode'
- keeps the cartridge port free
- powered through Mini-USB connector
- controlled through buttons and IEC.
- *NO* Ethernet support yet in stand alone mode!

Planned features

Built-in copier
...

Hardware Specifications

1541U

Board size: 68 x 100 mm
250k-gate FPGA
Full size 6-pin DIN connector (IEC)
512 kB SRAM
2 MB Flash ROM
32 MB SDRAM
Full size MMC / SD card compatible (Mini/Micro SD possible with adapter)
Stereo audio output
6-pin expansion pin-header for connection to tape port (for C2N emulation), or other future features.
CS8900a ethernet on board (-plus version only)

1541U-II

Board size: 62 x 84 mm (about 30% smaller than the 1541U)
Sturdy plastic case, enforced with glass fiber
700k-gate FPGA
MicroSD card compatible slot (instead of a full-size SD)
USB host port (supports Mass storage class only)
real-time-clock function, for correct file time and date
optional connection to tape port (tape extender) for playing .tap files

Known Problems

Needs detailed explanation.

Freezer bug
Ethernet bug

Notes

codebase64.org has "How the 1541U freezer works" or "Safely freezing the c64" by Gideon Zweijtzer
Commodore Free Issue 35 has an interview with Gideon Zweijtzer
Lotek64 Issue 26 has a german review on the 1541 Ultimate

Wikipedia deleted the page on the 1541 Ultimate (twice actually). Due to "Unambiguous advertising or promotion" the last time. Well - WiPeD 1541 Ultimate tries to recover it.

Software

Just three basic categories as of yet.

Firmware

Please note that all these archive contents are available from 1541ultimate.net and newer versions may be available there!

1541u_Firmware_v17beta.rar - includes 1541u-firmware-v17b.pdf and 1541u_v1.7beta.zip
1541u_Firmware_v16.rar - includes 1541u-firmware-v16.pdf and 1541u_v1.6.zip
1541u_Firmware_v15.rar - includes 1541u-firmware-v15.pdf and 1541u_v1.5.zip

inofficial

1541-Ultimate-MK1-2.6d.o918r4.zip - Obliterator918′s custom 1541 Ultimate Firmware for “mark 1″ units, Version 2.6d.O918.4 Based on Gideon’s SVN revision 131.

Software requiring special features

Listing software that requires one or another special feature only available on "modern" hardware and/or emulators, such as the 1541U, Chameleon or VICE.