Fast Load

This section is about various fast-loaders and copy-protection. Most commercial software for the C64 and C128 had copy-protection and especially for the C64 this also included a fast-loader. The fast-loader was especially needed for most C64 owners who did not have JiffyDOS. I've seen many cracked games (copy protection removed) that do not include a fast loader and they can be annoying to play (unless you have an emulator or JiffyDOS).

Let's take a deep dive into some of these to see how they work. Some are better = faster than others, as we'll see and discuss their merits. Some are better = harder to duplicate; we'll talk breifly about these without going into details of disk duplication. The following are fast-loaders for the C1541 from commericial publishers:

This last one is a home-brew fast-loader for the C1581:

Project Firestart

Comparison

We can compare these fast-loaders on a number of a features.

	Microprose type 1	Microprose type 2	Sega	Access	Epyx	GEOS	Project Firestart
Drive type	1541	1541	1541	1541	1541	1541	1581
Blank screen	no	no	yes	no	yes (loading)	no	no
Interrupts allowed	no	no	no	no	no (loading)	no	yes
Disk Header	modified	modified	standard	standard	standard	modified	standard
Directory structure	modified	standard	standard	standard	not used	modified	standard
Allow wildcard in filename	yes	no	no	yes	n/a	n/a	yes
File structure	custom	custom	standard	standard	custom	custom & standard	standard
Sector structure	custom (376 bytes)	custom (256 bytes)	standard (256 bytes)	standard (256 bytes)	custom (240 bytes)	standard (256 bytes)	standard (256 bytes)
Sector decoding time	0.0 ms	18.8 ms	25.5 ms	25.5 ms	0.0 ms	25.5 ms	0.0 ms
Head stepping speed (ms / half-track)	7.8	12.5	5.5	15.0	10.0	4.0~7.5	3.0
Disk → C64 transfer	57 µs/byte	50 µs/byte	87 µs/byte	131 µs/byte	39 µs/byte	98 µs/byte	48 µs/byte
C64 → Disk transfer	1300 µs/byte	147 µs/byte	422 µs/byte	1300 µs/byte	1050 µs/byte	100 µs/byte	1024 µs/byte
C64 memory footprint	under 0.25K	1.0K	under 1.75K	under 1.0K	under 0.75K	about 3.5K	about 0.5K (w/o save)
Needs KERNAL	yes	no	no	yes	no	yes	no
Load $D000~DFFF	I/O	I/O	RAM	I/O	RAM	I/O	I/O
Alters User Port	yes	yes	yes	yes	maybe (uses default)	no	no
Requires Unit 8	yes	yes	yes	no	yes	no	no
Write file/sector	no	no	no	no	yes	yes	yes
Other	Drive reads 5 blocks before each file.	Fast transfer 256 bytes before each file.		Slow transfer 512 bytes before each file.	No data checksum. Always loads multiples of 240 bytes.		Emulates KERNAL with nibble write.